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Geology, Earth Science

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Table of Contents

See: Geology, suppliers, (Commercial)

See: Charts, (Commercial)

See: Earth Science, (Commercial)

See Fossils, (Commercial)

See: Models, (Commercial): Calcium carbonate, Calcium fluoride, Copper oxide
Diamond, Graphite, Quartz, Sodium chloride, Zeolite, Zinc sulfide

Specimens, rocks, fossils, (Commercial) Earthquakes, Richter scale

36.3.01 Elements in the Earth's crust, abundance of elements

35.6.0 Geological time scales

35.5.0 Geology fieldwork

35.2.0 Minerals, properties of minerals

35.3.0 Ores and ore bodies

35.4.0 Rocks and minerals, general properties

35.7.0 Rocks, major groups of rocks


35.2.0 Minerals, properties of minerals
A mineral is a naturally occurring inorganic substance obtained by mining, having distinctive chemical and physical properties.
19.4.21 Mineral salts, food additives
Mineral wool, rock wool, stone wool, mineral fibres, used for seed germination, insulation, filters Minerals mined at the Broken Hill mines, Australia
Part 9. Geology, Earth Science (See Topsie Jewellery, Crystals, minerals, Melbourne) (market shop)
Actinolite, Ca2(Mg, Fe2+)5(Si8, O22)(OH, F)2
Adamant, traditional term for a very hard rock, especially diamond or corundum
Adamite, Zn2(AsO4)(OH)
Agate SiO2, a banded chalcedone, blue agate is light/bright blue
Albite sodium feldspar, Na(AlSi3O8)
Alkaline feldspars
Amazonite, microcline, KAlSi3O8, blue-blue/green crystals Amber, C12H20O, succinite
Amber (substance, smell, colour), (Chemistry)
35.14.3 Amethyst, SiO2
35.20.53 Ammolite Ammonium chloride (volcanoes), NH4Cl
35.20.3 Amosite amphibole,
35.17.0 Amphibole, common hornblende
Anatase, titanium (IV) oxide, TiO2, titanium dioxide
35.20.1 Anglesite, lead sulfate, lead vitriol, PbSO4
Anhydrite, CaSO4, "snake alabaster"
35.20.2 Antimony, Sb, natural antimony Apatite, Ca5[F (PO4)3]
Aragonite, CaCO3, calcium carbonate
Argentite, Ag2S, silver glance Arsenic, minerals containing arsenic
35.20.3 Asbestos, hydrous magnesium silicate Aquadag (See 4.) Augite
35.20.4 Azurite, basic copper carbonate, blue carbonate of copper, 2CuCO3.Cu(OH)2
35.20.5 Bauxite, Al2O3.2H2O Bentonite
Beryl, Be3Al2(SiO3)6
Biotite mica
34.9.6 Birth stones Bismuth Borax
35.20.6 Bornite, Cu5FeS4, bournonite
Brookite, TiO2 Bustamite, calcium manganese silicate, MnCaSiO6
Cadmoselite, CdSe, cadmium (II) selenide
Cadmium sulfide, CdS, greenrockite
35.19.0 Calcite, CaCO3, calc-spar Calcite crystals (Physics) Calomel, Hg2Cl2, (I) chloride
Coal, coal gas, coal tar Carbon, C
35.19.2 Carbonates, CO32-, mineral carbonates
35.22.7 Carving stones, Limestone, stone dust
35.20.7 Cassiterite, SnO2, tinstone
Celestine, SrSO4
Celsian, BaAl2Si2O8, barium feldspar
35.20.8 Cerussite, lead carbonate, ceruse, white lead ore, PbCO3
Chalcanthite, Copper (II) sulfate, CuSO4.5H2O (mineral)
35.14.4 Chalcedony, SiO2
35.20.11a Chalcocite, Cu2S
35.20.9 Chalcopyrite, CuFeS2
Chromite, FeCr2O4
Chrysoberyl, Al2BeO4, alexandrite
Chrysoprase, SiO2
Chrysotile, Mg3Si2O5(OH)4 Cinnabar, HgS, mercuric sulfide Calomel, mercury (I) chloride
35.23.1 Coal, coal tar
35.23.9 Coal seam gas, CSG, CTL
35.20.56 Coltan
35.20.11 Copper, Cu, natural copper
Coprolites, fossilized animal dung
Cornelian onyx, SiO2
35.20.12 Coronadite, lead manganese oxide, Pb2Mn8O16 Corundum, Al2O3 + (ruby, sapphire
Covelite, CuS
Crocidolite, riebeckite asbestos, tiger's eye, cat's eye
Crocoite, PbCrO4, red lead ore
35.20.13 Cryolite, sodium aluminium fluoride
Cuprite, Cu2O, red oxides of copper Diamond, C
Diatoms, Diatomaceous earth
35.19.1 Dolomite, CaMg(CO3)2
Emerald, Be3Al2(SiO3)6, natural emerald Emery Epsomite Erinite, Minerals containing arsenic
35.15.0 Feldspars group
35.20.14 Fluorspars, -(AlSi3O8)
Fluorite, fluorspar, calcium fluoride, CaF2)
2.6 Free element metals Fuller's earth
35.20.15 Galena, PbS, lead (II) sulfide, lead sulfide, lead glance, blue lead Garnet (Mn3, Al2, Si3, O12), or Mn3Al2[SiO4)3, manganese aluminium silicate, spessartine, spessartite
35.20.17 Goethite, FeO(OH), hydrated iron oxide, hydrous iron oxide
35.20.18 Gold, Au, natural gold, medical use
Glauberite, brongniartite, Na2SO4, CaSO4 Graphite, "lead pencil", "Aquadag", C
Greenockite, CdS, cadmium sulfide mineral
Greigite, Fe3S4, iron (II, III) sulfide, mineral
35.22.6 Gypsum, CaSO4.2H2O, calcium sulfate, plaster of Paris
35.20.19 Halite, NaCl, rock salt
Halloysite, Al4Si4(OH)8O10.4H2O, clay mineral, Dragonite, in plastics, flame retardants, paints
Hausmannite, manganese (II, III) oxide, Mn3O4, manganese tetroxide, insoluble in water, soluble in HCl
Hawleyite, CdS, cadmium sulfide mineral
35.20.20 Haematite, Fe2O3
35.17.0 Hornblende (amphibole group)
Hyalite, SiO2.H2O, silicon dioxide, glassy opal, (nacre)
Hydroxyapatite, Ca5[OH (PO4)3], Ca10(PO4)6(OH)2, similar to bones, so bioactive and used in surgical implants
Hydrozincite, Zn[(OH)3CO3], zinc bloom
Illite, KAl4(Si, Al)8O20(OH)4, is the most common clay mineral.
Iron, Fe, in ultra basic rocks, meteorites
35.20.21 Ilmenite, FeTiO3, titanoferrite
Jadeite (in Hornblende)
35.14.0 Jasper, SiO2, (in Quartz)
Kalinite, Aluminium potassium sulfate Kaolinite, Al4[(OH)8, Si4, O10], kaolin-type clays
Kerargyrite, AgCl, horn silver Kyanite, Al2(O, SiO4)
Langbeinite, K2Mg2(SO4)3, may be in "potash fertilizers"
35.20.55 Lapis lazuli
35.20.22 Lead, Pb Lead paint Lead tetra-ethyl, tetraethyl lead
Limonite FeO(OH), Fe2O3.xH2O
Mafic, rich in Mg or Fe, rocks rich in ferromagnesium minerals
Magnesia, magnesium oxide, MgO, periclase mineral
Magnesia, in Greece
Magnesite, MgCO3, bitter spar
35.20.23 Magnetite, Fe3O4 Magnetite, Magnet assortment, natural magnets
35.20.24 Malachite, Cu(OH)2.CuCO3, or Cu2[(OH)2, CO3], copper carbonate
35.23.3 Marble, CaCO3
Marbelite (swimming pools)
35.20.25 Marcasite, FeS2
Mascagnite, ammonium sulfate crystals in white to yellow stalactite-like masses, soft, water soluble, good cleavage Meerschaum
Melanterite, Iron (II) sulfate
35.20.26 Mercury
35.16.0 Mica group Birefringent mica
35.20.27 Millerite, NiS
Minium, Pb3O4, red oxide of lead, red lead
Mirabilite, Glauber's salt, sodium sulfate, Na2SO4.10H2O, glauberite mineral
35.20.28 Molybdenite, molybdic ochre, MoS2
Molybdite, molybdenum ochre, MoO2
Monazite, reddish phosphate rare mineral (Ce, La, Nd, Th)(PO4.SiO4) Montmorillonite (smectite)
Moonstone, K[(Si, Al)4O8], (Feldspars)
Muscovite mica
35.20.54 Nacre, mother of pearl
Nahcolite, NaHCO3, thermokalite, sodium hydrogen carbonate mineral, in evaporates
Natron, Na2CO3.10H2O (+ some NaHCO3 + NaCl, sodium carbonate decahydrate), in saline lake beds
35.20.29 Nickel, Ni
35.20.30 Nickeline, NiAs, niccolite, arsenical nickel Obsidian, volcanic glass
35.18.0 Olivine group (Mg, Fe)2SiO4
Onyx, SiO2
35.14.2 Opals, SiO2.nH2O Opal valuation Orpiment, Minerals containing arsenic
Orthoclase feldspar, KAlSi3O8, potassium feldspar
35.21.3 Pegmatite, beryl, topaz, tourmaline, zircon
Periclase, MgO, magnesium oxide Perlite, Obsidian
Perovskite, CaTiO3
Perthite, Group 1. Alkaline feldspars
35.23.4 Petroleum, crude oil
35.20.30a Palagonite
35.20.31 Platinum, natural platinum, Pt
35.20.32 Pyrite, FeS2, iron sulfide, iron disulfide, sulfuric pyrites, iron pyrites, fool's gold
Pyrolusite, manganese (IV) oxide, mineral, MnO2
35.20.33 Pyromorphite group, Pb5(PO4)3Cl, lead phosphate
35.20.34 Pyrrhotite, FeS, iron sulfide, magnetic pyrites
35.14.0 Quartz, SiO2, silica (rock crystal, rose quartz, smoky quartz, milky quartz, jasper, tiger's eye, adventurine, bloodstone)
35.23.5 Quartzite, SiO2 Realgar, As4S4, Minerals containing arsenic
35.20.35 Rhodochrosite, MnCO3, manganese carbonate, manganese spar
35.20.36 Rhodonite, MnSiO3, or ([Mn, Ca]SiO3)
Rock crystal, SiO2
Rose quartz, SiO2 Ruby
35.20.37 Rutile, TiO2, titanium (IV) oxide
Sagenite, TiO2, mineral
Sanidine Sapphire
35.20.38 Scheelite, CaWO4, calcium tungstate
35.22.6 Selenite, CaSO4.2H2O, satin spar
35.21.6 Serpentine, Mg6Si4O10(OH)8, antigorite
Siderite, FeCO3, chalybite, spathose iron
35.22.8 Siltstone, mudstone, marl, loess
Silica, SiO2, silica gel, silicon dioxide
Silicates, -(SiO4) (Chemistry)
35.14.1 Silicates (Geology)
Silicic acid, silicon oxyacid, metasilicic acid, H2SiO3
Silicon, Si
Silicon compounds
35.14.1 Silicates group, Opals, Amethyst, Chalcedony
35.20.39 Silver, Ag, natural silver
35.23.6 Slate (clay, mudstone, shales)
35.20.40 Smithsonite, ZnCO3 (basic zinc carbonate, ZnCO3.2ZnO.3H2O), calamine, zinc spar, galmei
Sodalite, Na8(Al6Si6O24)Cl2, igneous, plutonic mineral, changes colour in sunlight, self-adjusting sunglasses
35.20.41 Sphalerite, ZnS, zinc sulfide, zinc blende, mock ore, mock lead, black jack
Spinel, Al2MgO4
Spodumene, LiAlSi2O6, lithium aluminium silicate, forms 6 m crystals, grey-white ash when ignited
35.20.42 Stibnite, Sb2S3, antimonite, antimony glance, grey antimony
35.20.43 Stilbite, lamellar zeolite, hydrated sodium calcium aluminium silicate
Strontianite, SrCO3, strontium carbonate
Struvite, [(NH4)MgPO4.6H2O], ammonium magnesium phosphate
35.20.44 Sulfur, S, natural sulfur
Sulfur, S (Chemistry)
Sunstone, Ca(Al2, Si3, O3)Na(Al, Si3, O8), (Feldspars)
Sylvite, KCl, potassium chloride (Mineral)
35.23.7 Talc, Mg3Si4O10(OH)2
Tantanite, calcium titanium silicate, source of titanium, jewel stone
35.20.52 Tanzanite
Tellurium, natural tellurium, Te
Thorite, ThSiO4
35.20.45 Tin, Sn
Tin, Sn (Chemistry)
Titanite, CaTi(SiO4)O, sphene
35.20.37 Titanium (TiO2, titanium (IV) oxide, rutile)
Tobermorite, calcium silicatehydrate, Ca5Si6O16(OH)2.4H2O
35.21.3 Topaz, Al2SiO4(OH, F)2, (in Pegmatites), beryl, zircon
12.1.28 Trona, Na3H(CO3)2.2H2O, Prepare bath salts with sodium carbonate and with sodium sesquicarbonate
Tschermignite, NH4Al(SO4)2.12H2O, ammonium alum
Turquoise, CuAl6[(OH)2, PO4]4.4H2O, callaite Ulexite
35.20.46 Uraninite, UO2, pitchblende, pitch ore
35.20.47 Uranium, U, fission
Valentinite, Sb2O3, antimony bloom Vermiculite (Mg, Fe+2, Fe+3)3[(Al, Si)4O10](OH)2, 4H2O
Witherite, Barium carbonate, BaCO3
35.20.48 Wolframite (Fe, Mn)WO4
Wollastonite, Ca3(Si3, O9), calcium silicate, table spar, calc-flints
35.20.49 Zeolite (T5O10, T10O20 chains), e.g. tetrapropylammonium (TPA) ZSM-5, clinoptilolite
35.20.50 Zinc, Zn
Zinc blende, ZnS
35.20.51 Zincite, ZnO, red oxide of zinc
Zircon, ZrSiO4, zirconium silicate
Zirconia, ZrO2, zircon-favas Minerals mined at the Broken Hill mines, Australia
The minerals of Broken Hill are world famous because many of them are rare and beautiful.
Unfortunately, most of the rare minerals were found in the top sections of the mine where the sulfide ore minerals had been weathered
and oxidized by groundwater to produce a dazzling array of secondary minerals.
These areas of the mine are long worked out and are not producing ore or mineral specimens.
1. Ore minerals of the primary (sulfide) zone
2. Gangue (waste) minerals of the primary (sulfide) zone
3. Ore minerals of the oxidized zone Earthquakes, Richter scale
Earthquakes are violent moving or shaking of the Earth's caused by geological forces or volcanic activity.
Seismic waves are the vibrations from earthquakes that travel through the Earth.
They are recorded on seismographs that record a zig-zag trace of the amplitudes of ground oscillations.
Seismographs can detect earthquakes from sources anywhere in the world.
The Richter Magnitude Scale (Charles F. Richter, USA, 1935), an open-ended scale, is used to compare the size of earthquakes
from the logarithm of the amplitude of waves recorded by seismographs, adjusting for the distance between seismographs and the
epicentre of the earthquakes.
Each point on the scale presents a ten-fold increase in magnitude.
Magnitude is expressed in whole numbers and decimal fractions, e.g. strong earthquake magnitude 6.3.
The more recent Moment Magnitude Scale, devised for more precise study of great earthquakes, is a logarithmic scale of 1 to 10 that
enables seismologists to compare the energy released by different earthquakes on the basis of the area of the geological fault that
ruptured in the earthquake.

34.9.6 Birth stones
January, garnet | February, amethyst | March, bloodstone | April, diamond | May, emerald | June, pearl |
July, ruby | August, sardonyx | September, sapphire | October, opal | November, topaz | December, turquoise |.

35.24.0 Make artificial rocks
35.24.1 Make artificial igneous rocks, alum crystals, sulfur crystals
35.24.2 Make artificial rocks, sedimentary rocks
35.24.3 Make artificial rocks, metamorphic rocks
35.24 Make igneous rocks, alum crystals, sulfur crystals Borax
Borax mineral, [Na2B4O5(OH)4].8H2O, Tincal, found at edge of borax lakes.
Borax has a sweet alkaline taste, hydrated sodium borate, di-sodium tetraborate (III)-10-water, Na2B4O7.10H2O or
Na2(B4O5)(OH)4.8H2O, occurs in evaporite deposits, salt lakes, playas and efflorescence on soils in arid regions, in solution in some
hot springs.
Ulexite, alkaline taste, NaCaB5O6(OH)6.5H2O, hydrated sodium calcium borate hydroxide, is found associated with borax often in
evaporated lakes.
When ulexite is polished and has two smooth sides it has the fibre optic property of projecting an image through internal reflection from
the bottom of the to the top, so some people call it "TV stone"!
The fibres have the formula B5O6(OH)6.

35.15.0 Feldspars
Feldspars group, "field stone", -(AlSi3O8)
Feldspars occur as aluminosilicates of alkali metals and alkaline earths, have pink colour but red-green or yellow colour if impure and
some are white, e.g. sodium feldspar or albite, Mohs scale of hardness 6, white streak, glassy lustre, good cleavage in two directions,
conchoidal fracture, specific gravity 2.55-2.76.
It is the most common rock forming silicate in igneous rocks and some sedimentary rocks.
Feldspars are used in the interior of buildings as an ornamental veneer.
Feldspars have dull surfaces unless light strikes at just the right angle.
Feldspars in rocks may cause flashes of light because of reflection from two directions of cleavage at right angles to each other.
Feldspars are used in glazes and the manufacture of glass, enamels, polishes, and roofing material.

Feldspars are divided into two groups:
Group 1. Alkaline feldspars (K, Na)AlSi3O8, include orthoclase feldspar, microcline (KAlSi3O8), and sanidine, contain more
potassium and less or no sodium, calcium may substitute for potassium and sodium, monoclinic or triclinic crystal system, crystals
prismatic to tabular (also as irregular grains or cleavable masses), vitreous to silky lustre, colourless, white or pink (also green),
white streak, Mohs scale of hardness 6, two perfect cleavages at close to 90o, cleaves rather than fractures, not ferromagnetic, does
not react with hydrochloric acid.
Sanidine and orthoclase feldspar are the high temperature alkali feldspars, occur in alkali-rich igneous rocks, e.g. rhyolites and granites.
Microcline, the lower temperature alkali feldspar variety, occurs in granites, pegmatite dikes and hydrothermal vein deposits.
Orthoclase feldspar and microcline also occur in some metamorphic rocks and as discrete grains in immature sandstone.
Minor colourless or white plagioclase intergrown with pink microcline is called perthite.

Group 2. Plagioclase feldspars
Plagioclase feldspars, NaAlSi3O8, CaAl2Si2O8, include albite, anorthite, and andesine contain less or no potassium, triclinic
crystal system, tabular crystals (also as irregular grains or cleavable masses), vitreous to silky lustre, white to grey colour (also blue
to green), white streak, Mohs scale of hardness 6, two perfect cleavages at close to 90o, cleaves rather than fractures, not
ferromagnetic, does not react with hydrochloric acid, occurs mainly in mafic and intermediate igneous rocks, e.g. basalt, andesite.
Note the pink colour and cleavage, then turn the specimen in the light and note flashing surfaces.
To distinguish the two groups, the alkali feldspars all have the perthite structure and plagioclase feldspars have lamellar twinning.
Note the fine lines on a cleavage surface of plagioclase feldspar but not on orthoclase feldspar.

Feldspars include the following:
1. Potassium feldspar, orthoclase feldspar, KAlSi3O8
Brown to colourless, vitreous pearly lustre, translucent to transparent, Mohs scale of hardness 6-6.5, specific gravity 2.55, good
cleavage, brittle uneven fracture, massive granular crystals, monoclinic system, main constituent of many different rocks
2. Sodium feldspar, albite, NaAlSi2O8
3. Calcium feldspar, anorthite, CaAl2Si2O8
4. Barium feldspar, celsian, BaAl2Si2O8
5. Moonstones, K(SiAl)4O8, feldspar, gemstone have blue-white spots with a silvery colour like moonlight.
Moonstone is silvery-white, or milky white with a soft blue shimmer moving across its face as the stone is moved, called "adularescence".
The distinctive shimmer, caused by tiny albite inclusions, reflect and scatter light, mimicking the moon's glow, hence the gem's name.
6. Sunstones, Ca(Al2Si3O3)Na(AlSi3O8), feldspar, gemstone.

35.16.0 Mica group
See: Mica (Physics and chemistry)
See diagram Colours in mica (University of Melbourne)
The group has dark brown colour (biotite mica, Jean-Baptiste Biot, 1774-1863) or is colourless (muscovite mica), Mohs scale of
hardness 2.5-3, white streak, pearly to glassy lustre, single perfect cleavage and specific gravity 2.7, forms soft shiny flat flakes.
Muscovite mica or white mica, K2Al4Si6Al2O20(OH, F)4 contains no iron, so is clear and colourless.
Biotite mica, K2(Mg, Fe)6-4(Fe, Al, Ti)0-2(Si6-5Al2-3O20)(OH, F)4, is brown to black, and seen in granite as dark glittering specks.
Mica can be split into very thin elastic sheets that can be split into thin transparent layers.
On split faces the lustre is bright and pearly white but other faces are dull and rough.
Formerly, it was used in place of glass in beehives and in foundries, but now is used as a heat resistant material in windows, stoves, eye
shields, and sparkling makeup.
Mica is a poor conductor of electricity so it is used in electrical appliances.
The mica is used as a filler in plasterboard and paint, as a surface coating on welding rods, a release agent for coating foundry moulds,
and as spray-on decorative glitter.
Crush the specimen and note the sparkling surfaces.

35.17.0 Hornblende
Hornblende, NaCa2(Mg, Fe2+, Fe3+, Al5(Si, Al)8O22(OH, F)2
Hornblende, in the amphibole group, has dark green to black colour, Mohs scale of hardness 5 to 6, brown to grey streak, glassy to
dull lustre, two imperfect cleavages, uneven fracture, and specific gravity 2.9-3.4.
It forms small dark green to black crystals and is seen with biotite mica as dark patches in granite.

Actinolite is a similar mineral, Ca2(Mg, Fe2+)5(Si8, O22)(OH, F)2, that includes nephrite or nephrite jade, the jade popular in China.
Nephrite jade, Ca2(Mg, Fe)5(Si8, O22)(OH, F)2 is a fine grained massive variety of actinolite that is used for ornaments and sculptures.

Jadeite, is the other jade, Na(Al, Fe)SiO6, NaAl(Si2, O6), pyroxene group, from Myanmar (Burma).
Note the hexagonal cross-section of crystals, cleavage and colour of the hornblende specimen.

35.18.0 Olivine group
Olivine group (Mg, Fe)2SiO4, peridote, chrysolite
The olivine group has emerald-green to green-yellow colour, Mohs scale of hardness 6.5-7, white streak, glassy lustre, poor
cleavage, conchoidal fracture, and specific gravity 3.2-3.4.
It weathers easily to leave the rock brown because of iron oxide stain.
It occurs as sugary crystals that sparkle like quartz in basalt rocks.
Quartz and olivine seldom occur together in igneous rock.
Olivine occurs in the darkest rocks deficient in silicon.
It forms gemstone crystals, e.g. chrysolite, that are transparent and have a glassy lustre.
Volcanic "bombs" may have a lining of olivine crystals in the inner chamber.
Note the colour, hardness and density of the specimen.

35.19.0 Calcite
Calcite, CaCO3, calc-spar, Iceland spar
3.54.8 Prepare stalactite crystals
Calcite has white colour, in cracks in sedimentary limestone, Mohs scale of hardness 3, white streak, glassy lustre, good cleavage in
three directions (not at right angles), causing rhombohedral shape, conchoidal fracture, specific gravity 2.7 and greasy to touch.
Calcite occurs in four-sided crystals and as chalk and limestone.
It forms from evaporation of sea water and occurs in sedimentary and metamorphic rocks, but not in igneous rocks.
The crystallized varieties always break into little four-sided pieces when hit with a hammer.
Iceland Spar is a clear crystal with refractive index 1.49 and 1.66 causing a double refraction effect, birefringence, double image caused
by light polarization, used in the Nicol prism and in bomb-sights.
Sea animals use calcite to build a shell or outer skeleton.
Some types of calcite are used for building blocks, for making lime and in the glass and steel industries.
Weathering of pyrite liberates sulfuric acid that may change calcite into gypsum and other sulfates.
In limestone caves, calcite occurs as stalactites hanging from the roofs of limestone caves and stalagmites that grow up from the floor.
Ca(HCO3)2 (aq) --> CaCO3 (s) + H2O, (l) + CO2 (g)
Note effervescence with cold dilute hydrochloric acid, hardness and cleavage.
Turn the specimen in the light and note flashing surfaces.
If the specimen is a clear crystal, place it on a line and observe the refracted double line.

35.19.1 Dolomite
Dolomite, Ca(CO3)Mg(CO3), [Mg, Ca (CO3)2], (+ some silica), magnesium calcium carbonate
Dolomite has colour white to pink, Mohs scale of hardness 3.5-4, glassy to pearly to dull lustre, white streak, good cleavage in three
directions and specific gravity 2.84.
The term "dolomite" is a general term for rocks with a high ratio of magnesium to calcium carbonate.
Dolomite is used as sources of magnesium and in lining furnaces, fertilizers, ceramics, mineral wool, welding fluxes.
The medical use is to supplement calcium and magnesium deficiency.
Note the colour, hardness, density, lustre, and slow reaction to dilute hydrochloric acid.

35.19.2 Carbonates
Carbonates, CO32-, mineral carbonates
1. Azurite, 2CuCO3.Cu(OH)2: 35.20.4
2. Calcite, CaCO3: 35.19.0
3. Dolomite, CaMg(CO3)2: 35.19.1
4. Magnesite, MgCO3
5. Siderite FeCO3, chalybite, spathose iron
6. Smithsonite, ZnCO3: 35.20.40
7. Witherite, barium carbonate, BaCO3
8. Malachite CuCO3Cu(OH)2: 35.20.24
Calcite, dolomite and siderite are the main components of limestone.

35.20.1 Anglesite
Anglesite, lead sulfate, PbSO4
Anglesite has non-metallic lustre but is adamantine when crystalline and dull earthy, Mohs scale of hardness 3, specific gravity 6.3 and
is colourless, white, grey, pale yellow, transparent green, transparent to translucent colourless.
It may occur as groups of striated, blocky rhombs and flattened, simple, to complex prisms.
Anglesite, lead sulfate, PbSO4, is another widespread secondary mineral from the oxidized zones of the Broken Hill mine.
It is found in vughs (irregular voids) and fractures in all mines in the outcrop area.
The associated minerals are marshite, iodargyrite, pyromorphite, stalactitic goethite, and goethite matrix replaced by cerussite.

35.20.2 Antimony, Sb
See: Antimony, Sb (Chemistry)
Antimony occurs rarely as the metal, but in hydrothermal veins combined with other elements, e.g. sulfur. Arsenic, minerals containing arsenic
Arsenic, natural arsenic, As
Arsenic trisulfide, As2S3, orpiment, yellow pigment
Arsenopyrite, mispickel, arsenical pyrites, FeAsS
Anorthite, calcium feldspar, CaAl2Si2O8
Arsenolite, As2O3
Arsenopyrite, FeAsS
Erinite, Cu5(OH)4(As, O4)2, emerald-green, basic copper arsenate crystal, name from "Ireland"
Nickeline, niccolite, arsenical nickel, NiA: 35.20.30
Orpiment, tinsel, deep yellow colour ("gold-pimented"), As2S3
Realgar, As4S4, arsenic sulfide, ruby sulfur, ruby of arsenic, non-metallic lustre,
poisonous, red paint pigment, pesticide, "orpiment", highly toxic orange pigment

35.20.3 Asbestos
Asbestos is a group of fibrous silicate minerals, compact and hard, sometimes resembling petrified root of a tree, so was called
"mountain flax" or "salamander's wool".
The word is derived from the Greek meaning "incombustible".
The colours range from brown to yellow to green.
It usually occurs mixed with serpentine rock or mica schist.
Tiger's Eye and Hawk's Eye, used for men's cufflinks, are altered varieties of asbestos with wavy bands of light that glow and ripple as
you move them.
Asbestos is a fireproof substance and formerly was widely used as a heat insulator, for packing and for fireproof garments and fabrics.
The main asbestos mineral is white asbestos or chrysotile, hydrous magnesium silicate, Mg3Si2O5(OH)4, in serpentine mineral group.
Blue asbestos, crocidolite, is the most lethal to humans.
Brown asbestos is amosite.
Inhalation of the short asbestos fibres can cause the lung disorder asbestosis, mesothelioma lung cancer and bronchiogenic cancer.
The manufacture and use of white chrysotile asbestos products, banned in Australia in 2003, and since banned in many countries.
Do not cut old "fibro" sheets or pieces of asbestos, but replace the whole sheets with non-asbestos sheets.
The government may give advice on whether asbestos is present in buildings and how to get rid of it.
Asbestos is extremely toxic if inhaled into the lungs and causes two cancers, bronchiogenic carcinoma and mesothelioma.
It is safe to touch, but do not inhale the fibres.
Other forms of asbestos (amosite, anthophyllite, tremolite, actinolite and chrysotile) are not as dangerous by inhalation as crocidolite,
but should be treated similarly.
Specimens of ash should be stored in a sealed container until collection by a licensed waste contractor.
Correctly embedded asbestos, such as that found in geology teaching sample sets, does not pose a threat to health provided that the
embedding material remains intact.
In Queensland, Australia, asbestos samples sealed in plastic bags were available in school minerals sets, but some boys broke open the
plastic bags and handled the asbestos samples.
So the Queensland government was forced to take out the asbestos samples from the school mineral sets.

1.0 Blue asbestos
1.1 Crocidolite, Na2Fe3Fe2[(OH, F)Si4O11]2, riebeckite, asbestos, tiger's eye, cat's eye, blue asbestos, amphibole, is the most lethal
to humans.
Crocidolite asbestos and blue asbestos is Not permitted in schools.
Store demonstration specimens in sealed containers or embedded in plastic.
2.0 Brown asbestos (amosite, mysorite)
2.1 Amosite, amphibole (Mg, Fe)7(OH, Si4O11)2
3.0 White asbestos
3.1 Actinolite, amphibole, Ca2(Mg, Fe2+)5(Si8, O22)(OH, F)2, green-grey crystals, powdered mineral herbal medicine
3.2 Anthophyllite asbestos, amphibole (Mg, Fe)7(OH, Si4, O11)2
3.3 Chrysotile, Mg3Si2O5(OH)4, the main asbestos mineral, white asbestos, hydrous magnesium silicate, in serpentine mineral group
3.4 Tremolite, amphibole, Ca2Mg5(OH, F)2(Si4, O11)2
3.5 Byssolite, amphibole, Ca2Mg5(OH3F)2(Si4, O11)2. Augite
Augite (monoclinic, pyroxene, silicate), [(Ca, Mg, Fe2, Fe3, Ti, Al)2][(Si, Al)2O6]
Augite, Crystal systems, crystal habit, crystal form: 35.8 (See 4. Monoclinic)
Augite, Silicates group, polysilicates, polysilicon: 35.14.1 (See 3. Pyroxenes, MgSiO3, e.g. augite, jadeite, diopside). Meerschaum
Meerschaum, H4Mg2Si3O10
Meerschaum is found as floating white lumps and was formerly used for tobacco pipes and holders.
It is a soft, light-coloured, hydrated magnesium silicate found in Asian Minor.
If newly dug up, it lathers like soap and has been used as soap. Epsomite
Epsomite, hydrated Epsom salts, magnesium sulfate, bitter salt (kieserite), MgSO4.7H2O, constipation medicine.

35.20.4 Azurite
Azurite, 2CuCO3.Cu(OH)2, basic copper carbonate
Azurite has non-metallic vitreous lustre, Mohs scale of hardness 3.5-4, specific gravity 3.83, intense medium to dark azure blue colour,
transparent to translucent, colourless streak.
Azurite (copper carbonate) has a habit consisting of short tabular prisms, equidimensional plates, long spear-like crystals with
pyramidal terminations.
The associated mineral is malachite, Cu2[(OH)2, CO3].

35.20.5 Bauxite
Aluminium oxide, Al2O3, (Chemistry
Bauxite, Al2O3. x2H2O, hydrated aluminium oxide, is a residual sedimentary mineral that contains alumina and other oxides of aluminium
in the amorphous or crystalline state.
So it is more a rock-like mixture than a mineral.
Bauxite is a mixture of iron and aluminium hydroxides and oxides.
It is usually formed by weathering in tropical regions.
It is the most important ore for production of aluminium.
Bauxite has non-metallic lustre, white streak, no good cleavage, can be scratched by the finger nail, white to brown grey colour,
uneven fracture, specific gravity 2.0-2.5.

35.20.6 Bornite
Bornite, bournonite, Cu5FeS4
Bornite has purple to silver grey to black colour, Mohs scale of hardness 2.5-3, metallic lustre, black streak, poor cleavage, uneven
to conchoidal fracture, and specific gravity 5.09
It resembles gold or iron pyrite, but is more brittle than gold.
Bornite is called "cog wheel ore", because twinned crystals form in that shape.
Bornite may be a mixture of copper sulfides including Cu2S, (chalcocite) and CuS (covelite).
Note the twinning habit colour and density of the specimen.

35.20.7 Cassiterite
Cassiterite, tinstone, SnO2
Cassiterite has white to grey to black colour, with fractured pieces having brown colour, Mohs scale of hardness 1.5-2, white to grey
streak, metallic lustre with the crystal faces often brilliantly shiny, cleavage poor, specific gravity 6.6 -7.15.
It is quite brittle, usually occurs in ancient granite rocks, e.g. pegmatite, as small veins crossing the granite, and forms twin crystals.
Note the density, colour and hardness of the specimen.

35.20.8 Cerussite
Cerussite, lead carbonate, PbCO3, ceruse, white lead ore
Cerussite has a non-metallic and adamantine lustre, Mohs scale of hardness 3-3.5, specific gravity 6.55, is colourless or white or grey,
transparent to subtranslucent, but may be opaque white to wine yellow to brown-yellow to smoky brown, colourless streak.
It occurs as ore grade concentrations as a secondary mineral from the oxidized zones at Broken Hill where most of it is opaque white.
However, wine yellow, yellow brown, smoky brown, transparent and translucent examples occur.
It occurs as reticulated masses, complex arrowheads twinned crystals, and "jack straw" masses of tubular-shaped crystals.
It is found in ore bodies and is one of the most abundant minerals of the oxidized zone.
The associated minerals are malachite, [Cu2[(OH)2CO3], azurite, and bromian chlorargyrite.

35.20.9 Chalcopyrite
Chalcopyrite, CuFeS2, copper pyrite, copper iron sulfide, CuFeS2, has brassy yellow to green colour but often tarnishes bronze or iridescent to
form peacock ore, Mohs scale of hardness 3.5-4, dark green to black streak, metallic lustre, brittle, poor cleavage, conchoidal
fracture and specific gravity 4.1-4.3, brittle and antiferromagnetic.
It is the main copper ore and is also a "fool's gold".
Copper pyrite resembles gold or pyrite, but it has a deeper brass colour and pyrite has Mohs scale of hardness 6-6.5.
Pyrite is more brittle than gold and weathers to form the secondary minerals limonite, malachite and azurite.
Chalcopyrite, copper iron sulfide, occurs in veins in garnet, quartzite and garnet sandstone in ore bodies.
The associated minerals are argentiferous galena and arsenopyrite, FeAsS.
It may become magnetic when heated.
Note the crystal habit and softness of the specimen. Cinnabar
Cinnabar, HgS, mercuric sulfide, cinnabarite, quicksilver, HgS, mercuric sulfide (II) sulfide (calomel found with cinnabar), red crystals, native vermilion,
(red sulfide,
China red, vermilion, is used for Chinese chops, and was used in old paintings but is no longer used .
Cinnabar has brick red to scarlet colour, Mohs scale of hardness 2-2.5, red to scarlet streak, diamond-like lustre, but sometimes
darker non-metallic lustre, uneven fracture, specific gravity 8.19.
It is the most important mercury ore and is linked with volcanic activity, dangerous medicine.
Calomel, mercury (I) chloride, is a similar mineral.
Note the density, cleavage and colour of the specimen. Calomel
Calomel, mercury (I) chloride, Hg2Cl2, mercury (I) chloride, mercurous chloride, horn quicksilver, horn mercury, similar to cinnabar and found with it.
Note the density, cleavage and colour of the specimen.

35.20.11 Copper
Copper, Cu, natural copper
See: Copper (Chemistry)
See: Copper compounds, (Chemistry)
Copper has copper colour that tarnishes to green, copper red on a fresh surface but usually dark because of dark tarnish, metallic lustre,
no cleavage, jagged fracture, copper red shiny streak, Mohs scale of hardness 2.5-3 and specific gravity 8.96.
The rare native copper, Cu, occurs as rounded branches often with green or blue spots.
Nowadays it occurs in mainly sulfide ores in veins or on the surface of crevices in sandstone, slates and igneous rocks.
Pure copper is malleable, ductile and can be cut into slices.
It has high thermal and electrical conductivity and resistance to corrosion so it is an excellent electrical conductor.
Copper combines with zinc to form brass and combines with tin to form bronze.
The name copper comes from the island of Cyprus. Copper, Cu, natural copper, has arborescent forms in large cavities, four-sided
prisms, elongate octahedrons with repeated branches.
Also, stalactitic or dendritic masses in wire-like groups and nail head crystals.
Associated minerals are cuprite, Cu2O, red oxide of copper, and malachite, [Cu2[(OH)2, CO3] in weathering zone of copper deposits.
Note the colour, crystal form and ductility of a native copper specimen.

35.20.11a Chalcocite
Chalcocite, Cu2S, copper (II) sulfide, copper glance mineral, grey-black-blue, possibly iridescent, dark grey streak, Mohs scale of
hardness 2.5-3, may be formed from other minerals, e.g. bornite, crystals almost hexagonal, igneous or metamorphic in copper deposits.

35.20.12 Coronadite
Coronadite, Pb2Mn8O16
Coronadite (lead manganese oxide, formerly called psilomelane), occurs as massive, stalactitic, shawls, cellular, botryoidal habit,
sub-metallic glossy to earthy lustre, Mohs scale of hardness 5-6, S.G. 5.53, colour black to brown black, streak brown black.
Coronadite (lead manganese oxide) originally referred to as psilomelane, is massive, stalactitic, shawls, cellular, botryoidal habit.
Abundant in the upper levels of the oxidized zone and outcrop with associated mineral goethite forms the matrix for secondary minerals. Corundum
Corundum, Al2O3 + chromium, iron, titanium, (Mohs scale of hardness 9, ruby, sapphire)
Aluminium oxide, Al2O3, (Chemistry
Corundum as ruby contains Cr and is always red.
Sapphire contains Fe and Ti and is always blue-green, so a ruby is sometimes called a "red sapphire".

35.20.13 Cryolite
Cryolite, sodium aluminium fluoride, Na3AlF6
Cryolite has colourless to white to yellow colour, and sometimes purple to black colour, Mohs scale of hardness 2.5-3, white streak,
greasy to glassy lustre, no cleavage, uneven fracture and specific gravity 2.95-3.0.
The refractive index is 1.34 so the specimen almost disappears in water.
Colourless rare mineral used as a flux in electrolytic production of aluminium from bauxite, and is manufactured synthetically.
Note the disappearance in water, no salty taste and density of the specimen. Emery
Emery is the naturally occurring mixture of the mineral corundum, magnetite and others, is very hard and is used as an abrasive both as
powder or as blocks or wheels.

35.20.14 Fluorspar
Fluorspar, CaF2 (fluorite, calcium fluoride, blue john, Derbyshire spar), has many colours, colourless if pure but usually purple or green or
yellow, depending on dissolved impurities, Mohs scale of hardness 4, white streak, glassy lustre, good cleavage in four directions,
specific gravity 3.0-3.3.
Coloured specimens may fluoresce in ultraviolet light or glow when heated.
It occurs in veins in igneous rocks and can form twin crystals.
Large crystals have been carved into small vases.
It is used as a flux to smelt metals and to produce fluorine.
The name comes from the Latin "fluo", meaning "to flow" because it melts at a low temperature.
Note colour, hardness, cleavage and possible fluorescence of the specimen.

35.20.15 Galena
Galena, PbS, lead glance, blue lead, silver grey to black colour, Mohs scale of hardness 2.5, lead grey streak, metallic lustre, good cleavage in four
directions, and specific gravity 7.2-7.635.
It can mark paper and when hit with a hammer, breaks into perfectly cubic pieces because of its cubic cleavage.
Tetraethyl lead [lead (IV) tetraethyl] was formerly used as an "anti-knock" agent in petrol (gasoline), but not now, because lead is toxic.
Lead is used in X-ray shields, lead cell accumulators, ammunition, fishing sinkers, solder and type metal.
Galena is the most important lead ore and is the main lead ore mineral at Broken Hill, Australia.
The silvery metallic lustre and cubic appearance characterize galena, density of 7.5.
Galena is also the source of much of the silver at Broken Hill, Australia, because silver atoms can substitute for lead atoms or be present
within minerals such as acanthite (Ag2S) that have formed within the galena.
Note the density, and cleavage in the specimen.

35.20.17 Goethite
Goethite, FeO(OH), hydrous iron oxide, needle iron ore, acicular iron ore, has adamantine to dull lustre, but silky in some fine, or scaly, or fibrous
varieties, Mohs scale of hardness: 5-5.5, specific gravity 3.3-4.3, brown-yellow to dark brown colour, brown-yellow streak.
Limonite (brown iron ore, brown haematite, brown ironstone, is a cryptocrystalline mixture of mainly goethite, a weathering product
of all iron deposits and in hydrothermal veins, with associated mineral coronadite.
It has a habit consisting of botryoidal, mamillary, stalactitic masses and crusts, and it is abundant in the gossanous capping of ore bodies.

35.20.18 Gold, Au
See: Gold (Chemistry)
Gold, E 175, has copper yellow colour like butter, Mohs scale of hardness 2.5-3, gold to yellow streak, metallic lustre, no cleavage,
jagged fracture, and specific gravity 19.3, is malleable, ductile and can be cut into slices.
Gold is a widely distributed metal and always occurs in a metallic state, generally as an alloy with silver, copper or iron.
It occurs in thin irregular hydrothermal veins in a quartz reef, placer deposits and conglomerates.
Gold does not tarnish, so it has been used as the universal standard of exchange.
Specks of gold can be separated by "panning" so that the greater weight of the gold causes it to settle, leaving the gravel at the surface.
The "white gold" used in jewellery and decorating pottery is usually an alloy of gold and nickel, but used in dentistry it is an alloy of gold
and platinum.
3.2.2 Carat (Gold)
Pure gold is rated at 24 carats, so 18 carat gold contains six parts of an alloy.
Gold leaf, 23-24 carat, is gold beaten into very thin sheets for gilding decoration and electrical contacts, e.g. gold leaf electroscope.
The concentration of gold in sea water is about 10-30 g / km2, but no profitable method of extraction is known.
The red-purple alloy guanin, prized by pre-Columbian Indians in the Cuba region, was an alloy of gold, silver and copper.
Note the colour, and density of the specimen.

35.20.19 Halite
Halite, rock salt, NaCl
See: Sodium chloride, (Chemistry)
Halite has colourless or white colour, Mohs scale of hardness 2, white streak, glassy lustre, good cleavage to break into cubes,
conchoidal fracture, specific gravity 2.1-2.6.
The cubic crystals may have an indentation in one surface.
It forms from evaporation of sea water.
It may rise from deep layers to form massive salt domes and act as an oil trap.
Halite has a characteristic sharp taste.
The inland salt trade was once important for many places, e.g. Salzburg.
Table salt is always snowy white but natural salt has many different colours because of impurities.
A red colour is caused by ferric oxide (iron oxide), grey is caused by clay, and brown is caused by plant matter.
Used as table salt, road salt and glass manufacture.
In the Bible, Matthew 5: 13, "Ye are the salt of the earth: but if the salt have lost his savour, wherewith shall it be salted? It is
thenceforth good for nothing, but to be cast out, and to be trodden under foot of men."
Although pure sodium chloride cannot lose its saltiness, the rock salt used in biblical times often contained impurities.
If the sodium chloride content was leached away or lost by evaporation in very hot countries, the "salt" could indeed lose its salty taste.
Also, fine grain salt may taste saltier than coarse grain salt due to the greater surface to volume ratio so that more salt dissolve in the
saliva and reach the taste receptors on the tongue.
The evaporates from sea water salt pans are not pure sodium chloride because they may contain over 10% magnesium chloride to act
as a desiccating agent and assist food preservation.
Note the cleavage at right angles and the taste of salt in the specimen

35.20.20 Haematite
Haematite, Fe2O3, hematite, iron glance, specularite, antiferromagnetic.
Iron (III) oxide, Fe2O3, ferric oxide
Haematite has grey to black and red to brown colour, Mohs scale of hardness 5-6, red to brown streak, metallic to dull lustre, no
cleavage, uneven fracture, specific gravity 5.26.
It is weakly magnetic.
The crystalline form is black and shiny.
It is an important iron ore and is used in paints as a pigment and in jeweller's rouge polish.
Haematite is antiferromagnetic, because the Fe crystallizes in a structure with oxygen ions, in an hexagonal close-packed framework in
a plane, but it is antiferromagnetically coupled between the planes.
Antiferromagnetism occurs when the A and B sublattice moments are exactly equal but opposite, so the net magnetic moment is zero.
Note the red to brown streak and hardness of the specimen.

35.20.21 Ilmenite
Ilmenite, FeTiO3, has black colour and gives a black powder as in "black sands", Mohs scale of hardness 5-6, brown to black streak, metallic
lustre, no cleavage, conchoidal to uneven fracture, specific gravity 4.70-4.79.
Ilmenite is slightly magnetic.
The particles have been weathered from basic igneous rocks.
Note the density, lustre and streak of the specimen. Kaolinite
Kaolinite, Al2(OH)4(Si2, O5), Al4Si4O10(OH)8
Kaolinite, known as white clay, pipe clay, ball clay and China clay, is used for making pottery.
Kaolinite, commonly potassium alum, is a combination of potassium and aluminium sulfates,
Al2(SO4)3.K2(SO4).24H2O, KAl(SO4)2.11H2O.
It is a weathering product of feldspars, known as white clay, pipe clay, ball clay, Cornish clay and China clay, kaolin (also dickite
and nacrite minerals) is used in the manufacture of fine porcelain that is almost pure kaolin.
The cheaper grades are made with the addition of feldspar.
It is a soft white powder, insoluble in water, dilute acids or alkalis.
Kaolin clay contains mainly kaolinite and some illite.
Kaolin is ingredient of anti diarrhoea medicines to absorb bacteria and increase the bulk of faeces.
It is very astringent and is used for purifying water.
Soda alum or chrome alum are similar combinations where the potassium has been replaced by the corresponding metals. Kyanite
Kyanite, Al2(O, SiO4), disthene, munkrudite, cyanite, rhaeticite (white grey kyanite) (Greek: kyanos, blue), is an aluminosilicate mineral,
Mohs scale of hardness 4-5 and 6.5-7 depending on the direction of the cleavage planes, colourless streak, vitreous lustre.
Found in aluminium-rich metamorphic pegmatites and sedimentary rock.
Used in refractory and ceramic products, electrical insulators, abrasives, gemstones.
Elongated, columnar crystals.
Anisotropic, i.e. two different harnesses on perpendicular axes.

35.20.22 Lead, Pb
See: Lead (Chemistry)
Lead rarely occurs as the metal.
It has a metallic lustre, a dark grey colour and high specific gravity of 11.35.
Lead, Pb, occurs mainly as the lead ore galena (lead sulfide, PbS).
It is characterized by a metallic silver lustre and cubic fracture.
Cerussite (lead carbonate, PbCO3) and anglesite (lead sulfate, PbSO4) are found in areas where galena has been weathered or
exposed to oxidizing groundwater.
Typically this occurred at or near the surface.
Lead was used in water pipes, roofing and pigments, but is now mostly used in batteries for vehicles and other equipment.

35.20.23 Magnetite
Magnetite, Fe3O4, iron (II, III) oxide (FeO.Fe2O3), Fe2+Fe23+O4
Magnetite nanoparticles, Ferrofluid (product on sale)
Iron oxide (black iron oxide), is a mixed base, Fe3O4
Magnetite (iron (II) diiron (III) oxide, magnetitum, ferrosoferric oxide, loadstone, triiron tetroxide, black magnetic iron oxide,
ferrimagnetic magnetic lodestone, iron ore, black iron ore, black colour, Mohs scale of hardness 5.5 to 6.5, black streak, black powder,
metallic to dull lustre, no cleavage, conchoidal fracture, cube-shaped crystals, specific gravity 5.17.
It is called magnetic iron ore and has magnetic properties unlike any other mineral.
Formerly, it was the strongest magnet known when known as lodestone, which acts as a magnet when freely suspended, from
Magnesia, in Greece, but magnetite is no longer used as a magnet because much stronger and shaped magnets are needed.
It was probably first discovered in China where they used it for the first magnetic compasses.
Fragments of magnetite will be attracted to a magnet or will affect a suspended magnetic needle.
Magnetite has about 73% iron but it may also contain magnesium, chromium and titanium.
Magnetite is widely distributed in igneous rocks and volcanic ashes so it is an important iron ore used in smelting.
Magnetite is a folk medicine for liver function and a sedative.
Magnetite is ferrimagnetic, not ferromagnetic, because it contains two magnetic sublattices, A and B, caused by the Fe ion surrounded
by four oxygens and the Fe ion surrounded by six oxygens with uneven, antiparallel spins on the sublattices, [Fe3+] sublattice A
[Fe3+, Fe2+] sublattice BO4, to result in a net magnetic moment.
Some bacteria and the brains of bees and pigeons contain tiny magnetite crystals with perhaps a magnetic orientation function.
Note the magnetic property of the specimen and the streak.

35.20.24 Malachite
Malachite, copper (II) carbonate
See: Copper (II) carbonate, (Chemistry)
Malachite, Cu2(OH)2CO3, or CuCO3.Cu(OH)2, has a non-metallic lustre, adamantine to vitreous in crystals that are often silky in
fibrous varieties, dull lustre in earthy types, Mohs scale of hardness: 3.5 to 4, specific gravity 4.03, bright green and translucent
or chalk-green to lush-green colour, pale green streak.
Malachite, copper carbonate, [Cu2[(OH)2CO3], has botryoidal and sometimes velvety habit.
It is found in ore bodies as powdery to compact fibrous crusts and hemispherical aggregates.
The associated minerals are azurite and cerussite.

35.20.25 Marcasite
Marcasite, iron sulfide, FeS2, spear pyrites
Marcasite has brass to yellow colour with a green tinge, Mohs scale of hardness 6.5, green to black streak, metallic lustre, poor
cleavage, uneven fracture, and specific gravity 4.88.
So it is similar to pyrite but has radiating groups of twin crystals like a cock's comb.
Old specimens may oxidize to give off sulfur in an exothermic reaction.
Note the crystal habit of the specimen and compare the specimen with pyrite.
An old specimen may have a sulfur smell.

35.20.26 Mercury, Hg
See: Mercury (Chemistry)
Mercury, Hg, is a bright silvery coloured liquid that forms spherical droplets if spilt.
The relative specific gravity is 13.6.
Mercury was formerly called quicksilver and is the only metal that is liquid at room temperatures.
It rarely occurs free in rock cavities.
Mercury is used in thermometers, barometers, dental amalgams, silver-plating of mirrors and to separate gold from silver.
Note the appearance and movement of mercury in a mercury thermometer.
Do not allow students to touch mercury or to have any access to free surface metallic mercury.

35.20.27 Millerite
Millerite, NiS, nickel sulfide, hair pyrites
Millerite has brass to yellow colour, Mohs scale of hardness 3 to 3.5, green to black streak, metallic lustre, cleavage in 3 directions,
but not obvious in thin crystals, and specific gravity 5.3-5.5.
It forms thin, needle-like crystals called "hair nickel" with a bright metallic lustre.
It occurs in iron-nickel meteorites.
Note the crystal habit, colour and lustre of the specimen.

35.20.28 Molybdenite
Molybdenite, MoS2, has silvery grey to black metallic colour with a blue tinge, powder has the same colour as the crystal, Mohs scale of
hardness 1-1.5, blue to grey streak, can mark paper, good platy cleavage that forms flakes and specific gravity 5.0.
Molybdenum, Mo, occurs as branches in pipes of quartz but is one of the less common metallic elements.
The main use of this metal is in making blue pigment in glasses.
Because molybdenite resists repeated shocks, it is added to steel to improve its strength and toughness.
Note the greasy feel, the marks left on the fingers, and the blue streak of the specimen.

35.20.29 Nickel, Ni
See: Nickel (Chemistry)
Nickel is blue to white colour, Mohs scale of hardness 3.5, grey metallic streak, metallic lustre, no cleavage, specific gravity 8.9.
Native nickel is rare but it occurs in iron meteorites and in many different minerals, often oxidized to form green nickel "blooms",
hydrated nickel salts.
Nickel is weakly magnetic and malleable.
Note the weak attraction to magnets and density of the specimen.

35.20.30 Nickeline
Nickeline, niccolite, NiAs, arsenical nickel
Nickeline has copper red colour with a red tinge, Mohs scale of hardness 5 to 5.5, brown to black streak, metallic lustre, uneven
fracture, specific gravity 7.8, occurs in masses.
The name "nickel" comes from "Old Nick" (the devil) meaning it was worthless as a copper ore despite its similar colour.
Nickel is used for kitchen vessels, nickel electroplating and tougher nickel steel for armour plating and machinery parts.
An alloy of copper, zinc and nickel is called "German silver".
An applied magnetic field causes nickel to decrease in length so nickel wire may be used in some types of computers.
Note the colour, density, streak and sometimes an odour when heated.

35.20.30a Palagonite
Palagonite, mafic volcanic glass, altered by hydration of siderolemane or thrachylite.
Rock mineral fertilizer dust containing high levels of Si, Ca and trace minerals, used in compost-making and soil mixes.
It holds water well so is used in sandy soils.

35.20.31 Platinum, Pt
See: Platinum (Chemistry)
Platinum has steel grey colour of native platinum, but silver-white colour of pure metal, Mohs scale of hardness 4 to 5.5, steel grey
streak, metallic lustre, no cleavage, jagged fracture and specific gravity 14-19 for native platinum (platina, Spanish diminutive of
silver, plata) and density 21.45 for pure platinum, so one of the heaviest lustrous metals.
Platinum does not react with air, water or strong acids (except a mixture of hydrochloric acid and nitric acid).
Native platinum is very rare and occurs in alluvial deposits as scales and grains or cubic crystals.
Note the density, colour and hardness of the specimen.

35.20.32 Pyrite
Pyrite, iron pyrite, iron sulfide, FeS2 : See: Iron (II) sulfide (Chemistry)
Iron sulfide, FeS2, iron disulfide, sulfuric pyrites, pyrite, iron pyrites, fool's gold, marcasite
Pyrite has pale brass yellow colour, Mohs scale of hardness 6 to 6.5, black green to black brown streak, but green or brown to black
powder, metallic lustre, poor cleavage, conchoidal to uneven fracture, and specific gravity 4.9-5.2.
It is the most common sulfide mineral and occurs as cubic crystals.
It is found in lining cavities in faults and fractures in ore bodies.
The associated minerals are calcite and rhodocrosite.
It gives out sparks when struck with steel because of the fragments of sulfur igniting.
Pyrite was used in the old wheel lock firearms to produce the spark to explode the gunpowder.
Pyrite frequently shows traces of gold, silver, copper, nickel and arsenic.
It can occur in mineral veins where it was commonly mistaken for gold, "fool's gold", but it may be rich in gold or copper or sulfur.
It is used to manufacture sulfuric acid but is not smelted for iron production.
Pyrite may be polished and used in jewellery, but it is not malleable.
Pyrite may have characteristic striations on the surfaces of the crystal faces.
Pyrite, iron sulfide, is found in lining cavities in faults and fractures in ore bodies.
The associated minerals are calcite and rhodocrosite.
Pyrite is not magnetic but is attracted to a magnet.
Pyrite can be used in solar cells instead of silica.
Pyrite crystals were used as crystal detectors in "crystal set" radio receivers.
Note the hardness, streak and lustre of the specimen.

35.20.33 Pyromorphite
Pyromorphite, Pb5Cl(PO4)3, has non-metallic and resinous to adamantine lustre, Mohs scale of hardness: 3.5-4, and colour consisting of shades of
green, yellow, brown, grey and occasionally yellow-orange, sub transparent to translucent, specific gravity 6.5-7.1, colourless streak.
Pyromorphite is the most common lead phosphate, lead chlorophosphate.
It is a secondary mineral from the oxidized zone.
It has a large range of habits and colours including coatings and sprays, simple hexagonal prisms, stout hexagonal prisms, branching
aggregates, mamillated, botryoidal and colloform masses.
It is found all along the lode outcrop.
The associated minerals are coronadite, cerussite, secondary galena, and anglesite.

35.20.34 Pyrrhotite
Pyrrhotite, FeS, iron sulfide, has metallic lustre, Mohs scale of hardness 4, specific gravity 4.58-4.65, brown-bronze colour, black streak.
It is found in veins, zones and bands in ore bodies.
Pyrrhotite can be weakly magnetic but not at Broken Hill, where the associated minerals are calcite, galena, and chalcopyrite.

35.20.35 Rhodochrosite
Rhodochrosite, manganese carbonate, MnCO3, is a pink mineral found in fault zones along with other carbonate minerals, e.g. calcite.

35.20.36 Rhodonite
Rhodonite, manganese silicate, MnSiO3, or ([Mn, Ca]SiO3), specific gravity 3.69, is the most abundant manganese mineral found in the galena-rich
ore bodies.
It has a range of beautiful red pink "rosy" colours.

35.20.37 Rutile
Rutile, TiO2, titanium (IV) oxide, TiO2, titanium dioxide, nanopowder, fine powder, Anatase mineral, toxic if inhaled
Titanium (IV) oxide, powder, TiO2, titanium dioxide, colour white, opacifer, "white out" correction fluid, white pigments for tennis shoes,
household white paint, from mineral rutile, ilmenite FeTiO3, food additive, E171, the three mineral forms are anatase, brookite and rutile.
Rutile (titanium (IV) oxide, titanium dioxide, titania), has black or yellow to red to orange colour, Mohs scale of hardness 6-6.5,
brown streak, diamond-like lustre, good cleavage in two directions, conchoidal to uneven fracture, specific gravity 4.25.
Titanium is used in the aerospace industry to produce low density corrosion resistant steels.
Titanium dioxide has replaced lead in lead paint.
Titanium forms a protective layer in air, a passive oxide coating.
Note the lustre, hardness and streak of the specimen.

35.20.38 Scheelite
Scheelite crystals, calcium tungstate, CaWO4, has white to orange to grey colour, Mohs scale of hardness 4.5-5, white streak, diamond-like
to greasy lustre, poor cleavage, conchoidal to even fracture, and specific gravity 5.9-6.1.
The crystals are usually not water worn, so they keep their characteristic pyramid shape.
They are transparent to translucent and may be bright or dull, with rough surfaces.
It fluoresces blue in ultraviolet light.
This mineral occurs in veins in granite rocks with cassiterite or fluorspar.
Scheelite is an important ore of tungsten, W, used to increase the hardness of steel.
Note the crystal habit, fluorescence, and lustre of the specimen.

35.20.39 Silver, Ag
See: Silver (Chemistry)
Silver has silver white shiny colour that tarnishes to a black colour, Mohs scale of hardness 2.5-3, silver to white streak, metallic
lustre, no cleavage, jagged fracture, and specific gravity 10.5, if pure, but 10-12 if impure.
It is malleable and ductile, can be cut into slices, and is one of the best conductors of electricity.
It is a precious metal ranked next to gold and was once obtained from natural large masses but now is a by-product from the refining
of lead, zinc, copper and gold.
Silver can be moulded and shaped to form jewellery because of its pure white colour, softness and toughness.
Silver has massive, wire habit .
The associated minerals are gold and copper.
Silver occurs in a variety of minerals, but most of the silver is found as trace amounts of silver mineral locked up inside the lead
mineral, galena.
Sometimes silver occurs as big lumps, nuggets, of the metal itself.
Only silver ever comes out of the ground as a metal.
Lead and zinc are always locked away minerals, as is most of the silver.
Silver was largely used in the photographic industry although it has uses in jewellery, electronics and silverware.
Note the colour and tarnish of the specimen.

35.20.40 Smithsonite
Smithsonite, ZnCO3, calamine, zinc spar, galmei, ZnCO3,
(basic zinc carbonate, ZnCO3.2ZnO.3H2O),
has a non-metallic and vitreous to waxy lustre, Mohs scale of hardness 4-4.5, specific gravity 4.4-4.5, colourless to white to green to
pink to blue colour, colourless streak.
It is used as the main ingredient in zinc sun cream.
Calamine, is used in pink calamine lotion for treating sunburn.
Smithsonite, zinc carbonate, ZnCO3, is a widespread secondary mineral from the oxidized zones.
It occurs as rounded botryoidal aggregates resembling drops of wax and as honeycombed masses in ore bodies.
It is the most abundant secondary carbonate after cerussite.
The associated minerals are coronadite and goethite.
It is a widespread secondary mineral from the oxidized zones.
The associated minerals are coronadite and goethite.
It was formerly used to produce brass.
Calamine, Zinc carbonate, ZnCO3, harmful if ingested, calamine, zinc spar, smithsonite
Note the colour and colourless streak.

35.20.41 Sphalerite
Sphalerite, ZnS: See: Zinc sulfide (Chemistry)
Sphalerite, zinc sulfide, zinc blende, blende, mock ore, mock lead, black jack, zinc iron sulfide (Zn, Fe)S, has black colour, but other
colours also occur, Mohs scale of hardness 3.5-4, yellow to brown streak, diamond-like to submetallic lustre, good cleavage
in 6 directions, specific gravity 3.9-4.1.
The crystals may be transparent with brilliant sheen or translucent to opaque with metallic lustre.
It may glow if crushed, triboluminescent.
Zinc blende frequently occurs in compact masses with quartz, copper pyrites and galena.
Zinc is used to galvanize iron for roofing, for lining iron "tins" to prevent rust and in the manufacture of white paint and optical glass.
Sphalerite (zinc sulfide, ZnS) is the main zinc ore mineral at Broken Hill.
Good crystalline sphalerite is unusual at Broken Hill.
The colour of sphalerite varies with its impurities.
At Broken Hill it is black, but some rare large crystals have a deep red colour.
Note lustre, streak and softness of the specimen.

35.20.42 Stibnite
Stibnite, Sb2S3, antimonite, antimony glance, grey antimony
Stibnite, has grey to silver colour, Mohs scale of hardness 2, dark grey streak, metallic lustre, cleavage in one direction and specific
gravity 35.6.
Stibnite can mark paper, the crystals are curved and twisted, and it is the most important source of antimony, an important metal in the
printing industry.
Note the crystal habit of the specimen.

35.20.43 Stilbite
Member of the zeolite group, lamellar zeolite, hydrated sodium calcium aluminium silicate, Ca(Al2Si7O18).6H2O.
Stilbite, hydrated sodium calcium aluminium silicate, has more than one chemical formula, e.g. Na2, Ca, K2Al2Si7O18.7H2O, or
NaCa2Al5Si13O36.14H2O, has white to pink to yellow colour, Mohs scale of hardness 3.5-4, white streak, glassy to pearly lustre, good
cleavage in one direction, specific gravity 4.56.
Note how thin crystals stick together like a sheaf of wheat, lustre and density of the specimen.

35.20.44 Sulfur, S
Sulfur has yellow crystals with colour sometimes masked by impurities, Mohs scale of hardness 2, yellow streak, glassy lustre, poor
cleavage, conchoidal fracture, and specific gravity 2.07 (rhombic).
If held in a warm hand it may crackle, so it should be handled with care.
It burns with a small blue flame to form sulfur dioxide.
It is given off from volcanoes and deposited by the waters of some geysers and hot springs.
Sulfur is used in the manufacture of sulfuric acid, insecticides, medicines, matches, gunpowder and fireworks.
Note the colour, smell, and sensitivity to heat of the specimen.

35.20.45 Tin, Sn
Tin is very rare as native tin in placer deposits and tin is seldom used by itself.
Specific gravity 7.28.
Bronze is approximately 5% tin and 95% copper.
Other tin alloys include solder and pewter.
Tin is used in the glass industry.

35.20.46 Uraninite
Uraninite, UO2 (with UO3, Th, Pb, pitchblende, pitch ore), occurs usually as pitch-like masses (not crystals), has dull grey to black colour
with brown tint, Mohs scale of hardness 5-6, brown to black streak, metallic to dull lustre or a shine like pitch, poor cleavage,
conchoidal to uneven fracture, and specific gravity 8-10.6.
It is moderately hard and very heavy.
It undergoes radioactive decay to produce radium and helium, and other decay products.
Uranium is used in high grades of steel and is also the basic material used in atomic bombs and the world's nuclear power stations.
It is a rare material but large deposits occur.
Note the radioactivity, lustre, colour and streak of the specimen.

35.20.47 Uranium, U
Uranium (Chemistry)
1. Uranium occurs as uranium dioxide, UO2, in the mineral pitchblende, uraninite, that also contains radium and products of radioactive
Uranium ores usually contain Actinium.
2. Natural uranium is about 0.72% U235 (atomic number 92 + 143 neutrons) and 99.28% U238 (atomic number 92 + 146 neutrons).
The half life of U235 is smaller than the half life of U238, specific gravity 19.05.
The uranium decay series involves 14 steps as uranium decays eventually into lead.
3. Uranium fission is a nuclear reaction used to produce energy by neutron bombardment to form krypton-89 and barium-144 and
3 neutrons that can start a chain reaction.
The heat and radiation from the chain reaction must be controlled only by controlling the chain reaction.
235U92 + 1n0 --> 89Kr36 + 144Ba56 + 31n0 + λ
uranium-235 + neutron --> krypton-89 + barium-144 + 3 neutrons + radioactive decay constant
4. Uranium-238 spontaneously decays, first by alpha particle emission, alpha radiation (α radiation).
238U92 --> 234Th90 + 4He2 + γ
An alpha particle can be shown as 4He2 or 4α2.
uranium-238 --> thorium-234 + alpha particle + gamma rays
Uranium-238 eventually decays by 14 steps to 206Pb82.
Lead is more stable than the previous radioactive elements in the decay series.

35.20.48 Wolframite
Wolframite, iron manganese tungstate (Fe, Mn)WO4, has grey to brown to black colour, Mohs scale of hardness 4-4.5, brown to black streak,
dull lustre, good cleavage in one direction, and specific gravity 7.0-7.5.
Wolframite is an important ore of tungsten, W, used to increase the hardness of steel.
Note the cleavage, density and lustre of the specimen.

35.20.49 Zeolite
See: Zeolite, (Commercial)
18.7.69 Zeolite, swimming pools
Zeolite, e.g. tetrapropylammonium (TPA)ZSM-5, is a group of natural or synthetic hydrated aluminium silicates that appear to boil
when heated in a blowpipe, specific gravity 2.0-2.4.
They retain pores or channels in their crystal structure, easily gain or lose water, and have a high ion exchange capacity.
Zeolites are used in detergents as water softeners, and as catalysts for reforming petroleum products.
Sodium aluminosilicates, e.g. albite (NaAlSi3O8), jadeite (NaAlSi2O6)
"Zeolite A", synthetic laundry detergent, Na12Al12Si12O48. 27H2O

35.20.50 Zinc, Zn
See: Zinc (Chemistry)
Zinc is white to blue grey colour, grey streak, metallic lustre, good cleavage in one direction, specific gravity 7.1.
It almost never occurs as the metal but combined with sulfur or oxygen.
Zinc is brittle and must be heated to become malleable or ductile.
Zinc occurs mainly as sphalerite (zinc sulfide, ZnS).
At Broken Hill it has a black resinous appearance but rarely shows as big crystals.
Smithsonite (zinc carbonate, ZnCO3), caused by weathering and oxidation of ore by groundwater, is found in areas where the ore
body was at or near the surface.
Zinc is used in galvanized coatings of iron and steel.
It is also used in die cast alloy products, pigments and other industrial and agricultural applications.
Note colour, hardness and density of the specimen.

35.20.51 Zincite
Zincite, red oxide of zinc, ZnO, is found in metamorphic weathered deposits, specific gravity 5.66.

35.20.52 Tanzanite
Tanzanite is found near Mount Kilimanjaro, Tanzania, specific gravity 3.25-3.60.
It is a variety of the mineral zoisite (Ca2)(Al3)(Si2O7)(SiO4)O(OH), that has been artificially heated to become a gemstone, which
exhibits trichroism, i.e. alternately sapphire blue, violet, and burgundy colours, depending on crystal orientation.

35.20.53 Ammolite
Ammolite (aapoak, Kainah, gem ammonite, calcentine, korite), one of the rarest gemstones, is found in Alberta and on slopes of
Rocky Mountains, is composed of fossilized shells of ammonites, mostly aragonite crystals as in nacreous pearl shell, specific gravity
The pearly flashes of red, green and blue iridescence from polished ammolite is caused by interference of light rebounding through
layers of aragonite.

35.20.54 Nacre
Nacre, CaCO3, mother of pearl, specific gravity 2.68-2.86, pearls, an inner shell layer of some molluscs, is iridescent because of tiny plates of
aragonite held within an organic matrix, e.g. chitin, that strengthens the nacre.
It may produce a blister pearl attached to the interior of the shell, or a free pearl within the mantle tissues.

35.20.55 Lapis lazuli
Lapis lazuli, ancient intense blue semi-precious stone, lazurite mineral, (Na, Ca)8[(S, Cl, SO4, OH)2.(Al6Si6O24)], original
source of deep blue pigment ultramarine (beyond the sea), often occurs in crystalline marble, specific gravity 2.7-2.9.
This deep blue pigment much replaced by Prussian blue.

35.20.56 Coltan
See: Tantalum, Ta, Table of the elements
See: Niobium, Nb, Table of the elements
Coltan, "columbite-tantalite", Niobium and Tantalum metallic ore, from eastern Democratic Republic of Congo where "conflict tantalum"
is mined by minors and adult workers under adverse conditions to cause of genocides, heat resistant powder, tantalum holds charge
well so is in capacitors for smart phones, tablet computers and cell phones circuit boards, and its oxide in insulators.
High cost tantalum has been mined in Australia, Canada and Eritrea.

35.24.1 Make artificial igneous rocks, alum crystals, sulfur crystals
1. Crystallization of alum solutions is similar to the formation of coarse grained and fine grained igneous rocks.
Fill a test-tube one quarter full of powdered potash alum, [Al2(SO4)3.K2(SO4).24H2O], or [KAl(SO4)2.12H2O].
Slowly add just enough boiling water to dissolve the alum.
Hold the test-tube in a flame so that the mixture boils gently.
(a) Pour half the solution into a shallow metal container.
Place a piece of string partly in the liquid and add a seed crystal.
Stir the alum solution in the container so it cools quickly.
(b) Hang another piece of string in the test-tube so that it reaches the bottom and add a seed crystal.
Place the test-tube where it will cool slowly.
Examine the two solutions the following day and note the sizes of the crystals formed.
2. Melt some sulfur in a test-tube.
Fit a filter paper into a funnel and pour the molten sulfur into it.
As the sulfur cools it begins to solidify, first forming a crust on the surface.
As soon as the crust has formed, remove the filter paper from the funnel and unfold it, so that the still liquid sulfur in the lower part of
the filter can flow away from the crust.
Note a mass of small crystals on the underside of the crust.
Use a magnifying glass to observe the shape of these crystals.
3. Melt sulfur in a test-tube then pour it into a large beaker of water so that it solidifies rapidly to form plastic sulfur.
Take it out of the water and examine it after two hours.
The solid sulfur formed is very hard and you cannot see crystals with a magnifying glass.
However, very tiny crystals may be seen with a microscope.

35.24.2 Make artificial rocks, sedimentary rocks
1. Use a hammer to grind different coloured sedimentary rocks, keeping the colours separated.
Put coloured powdered particles in a glass jar as different layers.
Let water trickle down the inside of the jar so as not to disturb the layering until the water is 1 cm above the sediments.
Put the jar in the sun and let the water evaporate.
Wrap the jar in a thick cloth and break it with a hammer.
2. Mix Portland cement with water and put it in a mould until it hardens.
Break the set cement with a hammer and examine the outside and inside surfaces.
3. Mix dry cement with twice as much sand or gravel to form concrete.
Add water, mix thoroughly, and place it in a mould.
Leave the concrete to harden for several days.
Break the set concrete with a hammer and examine the outside and inside surfaces.
Note whether the concrete is easier or harder to break than the Portland cement.
4. Mix plaster of Paris with a small amount of water and put it in a mould until it hardens.
Stir rapidly or it will harden while being mixed.
Break the set plaster with a hammer and examine the outside and inside surfaces.
Note whether the plaster is easier or harder to break than the Portland cement or the concrete.

35.24.3 Make artificial rocks, metamorphic rocks
Fire a shaped piece of clay that has first been dried and put on a piece of broken pottery and heated it in a large crucible over a
Bunsen burner.

Tourmaline, NaFe3Al6[(OH)4(BO3)3, Si6, O18], (in pegmatites), double refraction, contains about 10 % boron.