1 / 48

Mineral Groups

Mineral Groups. Mineral Groups. Element Abundances. Silica (SiO 4 ) 4-. SILICATES. Common cations that bond with silica anions. All others: 1.5%. Mineral Groups. Non-ferromagnesian Silicates (K, Na, Ca, Al). Ferromagnesian Silicates (Fe, Mg). Oxides Carbonates

sirius
Download Presentation

Mineral Groups

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Mineral Groups

  2. Mineral Groups Element Abundances Silica (SiO4)4- SILICATES Common cations that bond with silica anions All others: 1.5%

  3. Mineral Groups Non-ferromagnesian Silicates (K, Na, Ca, Al) Ferromagnesian Silicates (Fe, Mg) Oxides Carbonates Sulfides/sulfates Native elements

  4. Silicates Actinolite(Tremolite) Ca2(Mg,Fe)5Si8O22(OH)2 Subclass: Amphibole Streak: White Hardness: 5 – 6 Lustre: Vitreous Density: 3.0 - 3.4Habit: Aggregate of acicular grainsColours: Greenish - white Crystal System: Monoclinic Cleavage: Uneven Fracture: Subconchoidal Magnetism: None Reaction with HCl: None Identification in hand sample:Habit and colour are best indicators. Associations:Metamorphosed calcareous sediments Comments:Higher in Fe than tremolite.

  5. Silicates Antigorite(Serpentine) Mg3Si2O5(OH)4 Subclass: PhyllosilicateHardness: 2.5 - 3.5 Streak: White Density: 2.6 Lustre: Greasy or waxy Habit: Lath-shaped crystals.Colours: Shades of green Crystal System: Monoclinic Cleavage: Perfect basal Fracture: Splintery or conchoidal Magnetism: None Reaction with HCl: Unknown Identification in hand sample:Lustre, colour and habit are indicative. Associations:Formed by hydrothermal action of mafics and ultramafics. Associations may include talc, calcite, brucite, chlorite, magnetite and chromite.

  6. Silicates Augite (Ca,Na)(Mg,Fe,Al,Ti)(SiAl)2O6Subclass: PyroxeneHardness: 5.5 – 6 Streak: White or gray Density: 3.2 - 3.5 Lustre: Vitreous Habit: Small blocky grains.Colours: Dark-greeny black colour Crystal System: Monoclinic Cleavage: Good / Uneven Fracture: Uneven to conchoidal Magnetism: None Reaction with HCl: None Identification in hand sample:Colour, cleavage and hardness are indicative of a pyroxene. Augite has 2 cleavage planes at 90°. Associations:Found in mafic to ultramafic rocks, and in high-grade metamorphs. Industrial / ecomonic uses:None.

  7. Silicates Biotite K(Mg,Fe)3(AlSi3O10)(OH)2Subclass: PhyllosilicateHardness: 2 – 3 Streak: Colourless Density: 2.7 - 3.4 Lustre: Vitreous Habit: MicaceousColours: Brown, black, reddish brown Crystal System: Monoclinic Cleavage: Perfect basal Fracture: Uneven Magnetism: None Reaction with HCl: Very weak Identification in hand sample:Colour and habit Associations:A very common mineral found in igneous, metamorphic and sedimentary rocks. Industrial / ecomonic uses:Altered into vermiculite, biotite is used as an insulation material and as filler in certain building supplies.

  8. Silicates Chalcedony  (Micro/Cryptocrystalline Quartz) -- SiO2Subclass: FrameworkHardness: 7 Streak: White Density: 2.7 Lustre: Vitreous / almost waxy Habit: Aggregate of very tiny SiO2 grains.Colours: White/gray or any colour Crystal System: Hexagonal Cleavage: None Fracture: Conchoidal Magnetism: None Reaction with HCl: None Identification in hand sample:Identified by hardness and texture/habit. Associations:Abundant in felsic rocks. Industrial / ecomonic uses:Used for making glass and as a source of Silicon.

  9. Silicates Chlorite (Mg,Fe,Al)3(Si,Al)4O10(OH)2Subclass: PhyllosilicateHardness: 2 - 2.5 Streak: Greenish white to white Density: 2.6 - 3.3 Lustre: Vitreous to somewhat pearly, waxy, dull Colours: Greenish-black (typical) Crystal System: Monoclinic Cleavage: Perfect {001} Magnetism: None Reaction with HCl: None Identification in hand sample:Colour and its low hardness are distinguishing characteristics. Industrial / ecomonic uses:None, however chlorite schist sometimes does have ornamental uses.

  10. Silicates Chrysotile  (Serpentine) Mg3Si2O5(OH)4Subclass: PhyllosilicateHardness: 2.5 Streak: White Density: 2.5 Lustre: Silky Habit: FibrousColours: Shades of green Crystal System: Monoclinic Cleavage: None Fracture: Uneven Magnetism: None Reaction with HCl: Unknown Identification in hand sample:Habit and colour and most indicative properties. Associations:Found by hydrothermal alteration of mafics and ultramafics. Associated with talc, calcite, brucite, chlorite, magnetite and chromite. Industrial / ecomonic uses:Used in 98% of world's production of asbestos.

  11. Silicates Epidote Ca2(Fe,Al)3(SiO4)3(OH) Subclass: SorosilicateHardness: 6 – 7 Streak: White Density: 3.4 - 3.5 Lustre: Vitreous Habit: Aggregate of small grains, striated faces, small but visible crystalsColours: Greeny, yellow-green, black Crystal System: Monoclinic Cleavage: Perfect Fracture: Uneven Magnetism: None Reaction with HCl: None Identification in hand sample:Slight colour difference between this mineral and olivine, but only under magnification (where details in the crystals can be seen). Also indicitive is the presence of a cleavage plane. Associations:Common accessory mineral in many regional and contact metamorphed rocks, particularly in more iron-rich rocks. Industrial / ecomonic uses:Semiprecious gemstone

  12. Silicates Garnet  (Pyrope, Grossular, Almandine)(Mg,Fe,Ca)3Al2(SiO4)3 Hardness: 6.5 – 7 Streak: White Density: 3.8 Lustre: Vitreous Habit: Small, well-formed crystalsColours: Darker reddy colours Crystal System: Isometric Cleavage: None Fracture: Conchoidal Magnetism: None Reaction with HCl: None Identification in hand sample:Crystal habit, colour and hardness. Industrial / ecomonic uses:Abrasives (particularly sandpaper), semi-precious gemstone.

  13. Silicates HornblendeCa2(Mg,Fe)4Al(Si7Al)O22(OH,F)2 Subclass: AmphiboleHardness: 5 – 6 Streak: White or gray Density: 3.3 - 3.4 Lustre: Vitreous Habit: Intergrown crystals, prismatic character of grains.Colours: Black Crystal System: Monoclinic Cleavage: 2 at 56° and 124° Fracture: Uneven / conchoidal Magnetism: None Reaction with HCl: None Identification in hand sample:Prominent striations, prismatic crystals and angle on cleavages is distinguishing. Associations:Forms in igneous rocks, and in the metamorphic rock amphibolite. Industrial / ecomonic uses: Ornamental.

  14. Silicates Muscovite KAl2(AlSi3O10)(OH)2 Subclass: PhyllosilicateHardness: 2.5 – 4 Streak: Colourless Density: 2.8 - 2.9 Lustre: Vitreous Habit: MicaceousColours: Colourless, to white or gray Crystal System: Monoclinic Cleavage: Perfect basal Fracture: Uneven Magnetism: None Reaction with HCl: None Identification in hand sample:Colour and habit are best indicators. Industrial / ecomonic uses:Used in the electronics industry in the manufacture of capacitors, transistors, insulators and certain window types. Also used as a filler in building materials.

  15. Silicates Olivine  (Forsterite (Mg) and Fayalite (Fe))Mg2SiO4 - Fe2SiO4Subclass: NesosilicateHardness: 6.5 – 7 Streak: Colourless Density: 3.3 - 4.3 Lustre: Vitreous Habit: GranularColours: Pistachio green, greenish yellow brown Crystal System: Orthorhombic Cleavage: Imperfect Fracture: Conchoidal Magnetism: None Reaction with HCl: Very weak Identification in hand sample:Pistachio-green colour and granular habit. Associations:Mafic and ultramafic igneous rocks. Associated with Ca-plag, Industrial / ecomonic uses:Peridote (a translucent variety of olivine) is considered a 'gem' mineral. Also used as a refractory sand and infrequently as an abrasive.

  16. Silicates Orthoclase  KAlSi3O8Hardness: 6 - 6.5 Streak: White Density: 2.6 Lustre: Vitreous Habit: Polysynthetic twinningColours: Pinky-white Crystal System: Orthorhombic Cleavage: Perfect Fracture: Subconchoidal Magnetism: None Reaction with HCl: None Identification in hand sample:Colour and evidence of exsolution with plagioclase. Associations:Very common in granite, granodiorite, syenite and related felsic rocks.

  17. Silicates Quartz (crystal) SiO2Hardness: 7 Lustre: Vitreous / glassy Density: 2.7 Habit: Crystalline Colours: Clear transparent Crystal System: Hexagonal Cleavage: None Fracture: Conchoidal Magnetism: None Reaction with HCl: None Identification in hand sample:Hardness, translucency and colour are indicators.

  18. Silicates Talc Mg3Si4O10(OH)2Subclass: PhyllosilicateHardness: 1 Streak: White Density: 2.6 - 2.8 Lustre: Greasy Habit: Compact masses, often no crystals.Colours: White, or brownish, dark green, gray Crystal System: Monoclinic Cleavage: Perfect Fracture: Uneven Magnetism: None Reaction with HCl: Unknown Identification in hand sample:Mineral is very soft and are often compact masses. Colour is typical and varies to brown, green or gray.

  19. Silicates Topaz Al2SiO4(F,OH)2Hardness: 8 Streak: White Density: 3.5 Lustre: Glassy Habit: Prismatic crystalsColours: Almost brownish, any colour Crystal System: Orthorhombic Cleavage: Perfect Fracture: Subconchoidal Magnetism: None Reaction with HCl: None Identification in hand sample:Resembles quartz, but harder. Associations:Quartz Industrial / ecomonic uses:Gemstone

  20. Silicates Zircon (ZrSiO4) Hardness: 7.5 Streak: White Density: 4.6 - 4.7 Lustre: SubadamantineHabit: Excellent tetragonal prismsColours: Colorless, red, brown, yellow, green or gray Crystal System: Tetragonal Cleavage: Imperfect Fracture: Conchoidal Magnetism: None Reaction with HCl: Unknown Identification in hand sample:Excellent crystalline habit, density and streak/colour are indicative. Industrial / ecomonic uses:Source of zirconium and hafnium

  21. Carbonates Azurite ---Cu3(CO3)2(OH)2Hardness: 3.5 – 4 Streak: Lighter blue Density: 3.8 Lustre: Vitreous, earthy (fine grained) Habit: Fine grained coating or fracture filling on rockColours: Azure blue Crystal System: Monoclinic Cleavage: Perfect Fracture: Conchoidal Magnetism: None Reaction with HCl: Strong Identification in hand sample:Colour is reliable, association with malachite is also indicative. Associations:Common mineral in the near-surface oxidized portion of copper-bearing hydrothermal sulfide mineral deposits. Associated with malachite. Industrial / ecomonic uses:A minor ore of copper, also has ornamental uses. Sometimes a pigment (when powdered).

  22. Carbonates Aragonite ----CaCO3 Hardness: 3.5 – 4 Lustre: Vitreous Streak: White Habit: Stalactitic aggregate of crystals or grains. Colours: Colourless or white Crystal System: Orthorhombic Cleavage: Pinacoidal Fracture: Subconchoidal Magnetism: None Reaction with HCl: Strong Identification in hand sample:Stalactitic habit, hardness (greater than that of calcite) and colour. Associations:Occurs in carbonate-bearing blueschist metamorphic rocks. Associated with glaucophane, lawsonite, pumpellyite. Also forms at or near the surface in cave and hot spring deposits. Industrial / ecomonic uses:Same as calcite, however abundance is much much less than that of calcite, thus having little economic value.

  23. Carbonates Calcite (massive) CaCO3Hardness: 3 Density: 2.7Streak: White Lustre: VitreousHabit: Fine grained aggregates (massive)Colours: Colourless, white, gray, yellow-brown, pink, rose red Crystal System: Hexagonal Cleavage: Perfect rhombohedral Fracture: Subconchoidal Magnetism: None Reaction with HCl: Strong Identification in hand sample:Recognized by hardness and cleavage. Dolomite and aragonite have higher densities. Associations:Common as a cementing agent in clastic sediments, or as fossil fragments. Essential constituent of limestone. Industrial / ecomonic uses:Used in the manufacture of portland cement (quicklime). Also used as a pharmaceutical (antacids, calcium supplements).

  24. Carbonates Calcite (sparry)  (Iceland Spar) ---- CaCO3 Hardness: 3 Streak: White Density: 2.7 Lustre: Vitreous Habit: Large crystals, some exhibiting common twin striaeColours: White Crystal System: Hexagonal Cleavage: Perfect rhombohedral Fracture: Subconchoidal Magnetism: None Reaction with HCl: Strong Identification in hand sample:Hardness, crystal habit and twin striae are typical. Associations:Common as a cementing agent in clastic sediments or as fossil fragments. Industrial / ecomonic uses:Used in the manufacture of portland cement (quicklime) and in the pharmaceutical industry. Comments:The transparent variety is called "Iceland Spar".

  25. Carbonates Dolomite ---- CaMg(CO3)2 Hardness: 3.5 – 4 Streak: White Density: 2.85 Lustre: Vitreous Habit: Crystalline or aggregate, some with twin striae. Colours: Pinky/peach, white, gray, brown. Crystal System: Hexagonal Cleavage: Perfect rhombohedral Fracture: Subconchoidal Magnetism: None Reaction with HCl: Weak Identification in hand sample:Harder than calcite Associations:Major constituent of dolostone (aka dolomite). Industrial / ecomonic uses:Used in manufacture of portland cement.

  26. Carbonates Malachite ---- Cu2(CO)3(OH)2Hardness: 3.5 – 4 Streak: Pale green Density: 4.0 Lustre: Earthy Habit: Very fine grained coating on other rocks, almost looks like paint.Colours: Copper green Crystal System: Monoclinic Cleavage: Perfect Fracture: Subconchoidal Magnetism: None Reaction with HCl: Strong Identification in hand sample:Colour is primary indicator, as well as habit. Associations:Common in near-surface oxidized portions of copper bearing hydrothermal sulfide mineral deposits. Industrial / ecomonic uses:Used as a minor ore of copper and also has ornamental uses due to vivid green colour.

  27. Carbonates Siderite ---- FeCO3Hardness: 3.5 – 4 Streak: White Density: 4.0 Lustre: Vitreous Habit: Aggregate of crystals or grainsColours: Tan brown (typical) Crystal System: Hexagonal Cleavage: Perfect rhombohedral Fracture: Uneven Magnetism: None Reaction with HCl: Weak Identification in hand sample:Identified by colour and hardness. Associations:Produced by hydrothermal alteration of limestone. May also occur as concretionary or oolitic forms in clay ironstones. Industrial / ecomonic uses:Sometimes used as an iron ore. Also used in pigments where a red or brown colour is desirable.

  28. Halides Fluorite --- CaF2 Hardness: 4 Streak: White Density: 3.1 - 3.3 Lustre: Vitreous Habit: Crystals, usually cubicColours: Commonly colourless, blue, purple or green, but any is possible. Crystal System: Isometric Cleavage: Perfect octahedral Fracture: Conchoidal Magnetism: None Reaction with HCl: Unknown Identification in hand sample:Cubic crystals, hardness and colour indicative. Associations:Common in hydrothermal mineral deposits associated with sulfides, carbonates and barite. Industrial / ecomonic uses:Main source of fluorine (which is added to drinking water, toothpaste, used as a flux in industrial uses and as part of CFCs)

  29. Halides Halite  (Salt) --- NaCl Hardness: 2 Streak: White Density: 2.1 - 2.2 Lustre: Waxy Habit: Crystalline (cubic)Colours: Colourless or white if pure, any colour if not Crystal System: Isometric Cleavage: Cubic Fracture: Conchoidal Magnetism: None Reaction with HCl: None Identification in hand sample:Has a salty taste. Cubic cleavage and hardness are indicative for the less brave geologists. Associations:Abundant in marine evaporite deposits and may form beds hundreds to over a thousand meters thick. Associated minerals include calcite, dolomite, gypsum, anhydrite and sylvite.

  30. Hydroxide Limonite-- FeO(OH) Hardness: 5 - 5.5 Streak: Yellow-brown Density: 2.7 - 4.3 Lustre: Earthy Habit: Fine grained aggregate, powdery coating.Colours: Orange, yellow-brown Crystal System: Unknown Cleavage: None Fracture: Uneven Magnetism: None Reaction with HCl: Very weak Identification in hand sample:Colour is best indicator, followed by habit. Associations:Common weathering product of iron-rich rocks. Comments:The fine brownish coloured mineral is usually weathered goethite.

  31. Oxides Chromite (FeCr2O4)Hardness: 5.5 Streak: Brown Density: 4.5 - 4.8 Lustre: Metallic to pitchy Habit: Fine grained aggregate.Colours: Black Crystal System: Isometric Cleavage: None Fracture: Uneven Magnetism: Weak Reaction with HCl: Unknown Identification in hand sample:Resembles magnetite and ilmenite, but not very magnetic and has a more resinous lustre. Associations:Found in mafic and ultramafic igneous rocks such as gabbro, peridotite, dunite and pyroxenite as an accessory mineral. Industrial / ecomonic uses:Only ore mineral for chromium.

  32. Oxides Corundum (Al2O3) Hardness: 9 Streak: White Density: 4.0 - 4.1 Lustre: Vitreous to adamantine Habit: Well-formed crystalsColours: Any. White, gray or gray-blue, or red (ruby), blue (sapphire), yellow, green.  Crystal System: Hexagonal Cleavage: None Fracture: Conchoidal Magnetism: None Reaction with HCl: None Identification in hand sample:Hardness is best indicator, crystal habit is good too. Associations:Gem quality corundum comes from metamorphed limestone or dolostone (needs high Al concentrations, here presumably from detrital deposits) Industrial / ecomonic uses:Used as a gemstone. High-quality ruby can be more valuable than diamond. Corundum is also used as an abrasive in sandpaper, polishing compounds, etc.

  33. Oxides Hematite (massive)  -- (Fe2O3) Hardness: 5 – 6 Streak: Deep red Density: 5.3 Lustre: Earthy Habit: Very fine grained aggregate of red crystals.Colours: Deep red Crystal System: Hexagonal Cleavage: None Fracture: Subconchoidal Magnetism: Weak Reaction with HCl: Unknown Identification in hand sample:Deep red streak and earthy lustre are indicative. SG may also be indicative. Associations:Produced by weathering or hydrothermal alteration of iron-bearing minerals. May be found in some syenite, trachyte, granite and rhyolite. Industrial / economic uses:Important ore or iron, sometimes used as a gemstone. Comments:May become magnetic when heated.

  34. Oxides Hematite (specular)  (Fe2O3) Hardness: 5 – 6 Streak: Deep red Density: 5.3 Lustre: Metallic Habit: Micaceous/tabular habit.Colours: Steel gray Crystal System: Hexagonal Cleavage: None Fracture: Subconchoidal Magnetism: None Reaction with HCl: Unknown Identification in hand sample:Shining gray metallic lustre and deep-red streak are indicative. Associations:Produced by weathering and hydrothermal alteration of iron-bearing minerals. Industrial / ecomonic uses:Important ore of iron.

  35. Oxides Magnetite (Fe3O4) Hardness: 5.5 - 6.5 Streak: Black Density: 5.2 Lustre: Dull metallic to splendentHabit: Granular habit of fine grains. Some octahedral crystals may form.Colours: Black Crystal System: Isometric Cleavage: None Fracture: Subconchoidal Magnetism: Strong Reaction with HCl: Unknown Identification in hand sample:Highly magnetic. Habit and colour are also indicators. Associations:Very common accessory mineral found in a wide variety of igneous and metamorphic rocks, usually as small grains. Industrial / ecomonic uses:Mined for iron. Crushed magnetite also been used as aggregate to make high-density concrete for specialized applications, such as nuclear reactors.

  36. Oxides Pyrolusite (MnO2) Hardness: 2 - 6.5 Streak: Black Density: 5.1 Lustre: Earthy Habit: Massive, compact, columnar or fibrous. Prismatic crystals are rare. Sometimes forms as dendritic coatings on other rocks.Colours: Black Crystal System: Tetragonal Cleavage: Perfect Fracture: Uneven Magnetism: None Reaction with HCl: Very weak Identification in hand sample:Will leave sooty marks if touched. Associations:Found in bog and marine deposits Industrial / ecomonic uses:Manganese is used to colour bricks.

  37. Phosphates Apatite Ca5(PO4)3( OH,F,Cl) Hardness: 5 Streak: White Density: 3.1 - 3.2 Lustre: Vitreous, glassy Habit: MassiveColours: Grayish blue-green, or any. Crystal System: Hexagonal Cleavage: Poor Fracture: Conchoidal Magnetism: None Reaction with HCl: Weak Identification in hand sample:Colour, crystal habit and hardness are good indicators. Associations:Common accessory mineral in all environments. Industrial / ecomonic uses:Source of phosphate used in fertilizers and other industrial applications. Fluorine is also extractable from apatite. Comments:Same stuff as in bones and teeth.

  38. Sulfates Alabaster  (Gypsum) CaSO4- 2H2OHardness: 2 Streak: White Density: 2.3 Lustre: VitreousHabit: Granular / massive form of gypsumColours: Colourless or white (typical) Crystal System: Monoclinic Cleavage: Perfect Fracture: Splintery Magnetism: None Reaction with HCl: Weak Identification in hand sample:Identified by hardness and good cleavage. Associations:Common in marine evaporite deposits. Industrial / ecomonic uses:Modern use is in gypsum wallboard used in construction. Used as an ornamental stone and for sculpture due to its softness.

  39. Sulfates Barite (BaSO4) Hardness: 3 - 3.5 Streak: White Density: 4.5 Lustre: Vitreous Habit: Fine grained aggregatesColours: Colourless, white, gray, yellowish, brown, reddish, bluish or greenish Crystal System: Orthorhombic Cleavage: Perfect Fracture: Uneven Magnetism: None Reaction with HCl: None Identification in hand sample:High specific gravity is best indicator, colour and fracture are also helpful. Associations:Common in hydrothermal veins, associated with galena, sphalerite, pyrite, quartz, fluorite and carbonates. Industrial / ecomonic uses:Primary ore for barium, also used as an additive to drilling mud (because of high SG). Has over 2000 uses in industry.

  40. Sulfates Selenite(Gypsum) CaSO4- 2H2OHardness: 2 Streak: White Density: 2.3 Lustre: Vitreous Habit: Large crystalline habitColours: Colourless, clear Crystal System: Monoclinic Cleavage: Perfect Fracture: Splintery Magnetism: None Reaction with HCl: Weak Identification in hand sample:Single large crystals of gypsum, typified by hardness and transparency. Associations:Found in marine evaporites. Industrial / ecomonic uses:Used in gypsum wallboard.

  41. Sulfides Chalcocite (Cu2S) Hardness: 2.5 – 3 Streak: Blackish lead-gray Density: 5.5 - 5.8 Lustre: Dull metallicHabit: Chunky fracture, massive habit.Colours: Blackish lead-gray Crystal System: Monoclinic Cleavage: Indistinct Fracture: Conchoidal Magnetism: None Reaction with HCl: None Identification in hand sample:Black colour with sooty appearance on weathered surfaces and sectile character are distinctive. Bronze-yellow on fresh surfaces. Associations:Found in the supergene-enriched zone of copper-bearing hydrothermal sulfide deposits. Industrial / ecomonic uses:Mined as a source of copper.

  42. Sulfides Chalcopyrite (CuFeS2) Hardness: 3.5 – 4 Streak: Greenish black Density: 4.3 - 4.4 Lustre: Metallic Habit: Fine grained to massive aggregates.Colours: Brass yellow, may be tarnished and iridescent. Crystal System: Tetragonal Cleavage: Poor Fracture: Conchoidal Magnetism: None Reaction with HCl: Very weak Identification in hand sample:Distinctive brassy-green colour. Has a richer yellow colour than pyrite and a lower hardness. Associations:Most common copper-bearing mineral, found in many hydrothermal sulfide deposits. Often associated with galena, sphalerite, pyrite and other sulfides. Industrial / ecomonic uses:Mined for its copper which has innumerable industrial uses.

  43. Sulfides Galena (PbS)Hardness: 2.5 Streak: Lead gray Density: 7.6 Lustre: MetallicHabit: Excellent cubic cleavage, crystals usually very evidentColours: Lead gray Crystal System: Isometric Cleavage: Perfect cubic Fracture: Subconchoidal Magnetism: None Reaction with HCl: Weak Identification in hand sample:Gives off a rotten-egg smell in HCl, very high SG, very metallic lustre. Associations:Very common in hydrothermal sulfide deposits. Associated with sphalerite, pyrite, chalcopyrite, quartz, calcite, fluorite, and/or barite. Industrial / ecomonic uses:Main ore from which lead is extracted, also a source of silver.

  44. Sulfides Pyrite (crystalline) FeS2 Hardness: 6 - 6.5Density: 5.0 Lustre: Metallic Streak: Greenish/brownish black Habit: Perfect cubic crystalline habit. Colours: Bronze-yellow Crystal System: Isometric Cleavage: Good Fracture: Conchoidal Magnetism: Unknown Reaction with HCl: None Identification in hand sample:Colour, hardness, streak and habit are best indicators. Gives off sparks when struck with a hard metal object. Associations:Most common sulfide mineral, almost always present in hydrothermal deposits. Industrial / ecomonic uses:May be used as source of iron or sulfur, but not normally of economic value.

  45. Sulfides Stibnite (Sb2S3) Hardness: 2 Streak: Lead gray Density: 4.6 - 4.7 Lustre: MetallicHabit: Range from fine to medium grains to prismatic crystals (with longitudinal striations). Complex terminations, radiating acicular groups.Colours: Lead gray, black, iridescent tarnish Crystal System: Orthorhombic Cleavage: Perfect Fracture: Subconchoidal Magnetism: None Reaction with HCl: Weak Identification in hand sample:Colour and small subhedral crystals are indicators. Also rather soft. Associations:Forms in low-temperature hydrothermal veins, or is deposited from hot mineral springs. Industrial / ecomonic uses:Important source of antimony (Sb)

  46. Native Elements Copper (Cu) Hardness: 2.5 - 3 Streak: Same Density: 8.9 Lustre: Metallic Habit: Massive, platey or dendritic habit.Colours: Light rose on fresh surface, copper-red on tarnished surface Crystal System: Isometric Cleavage: None Fracture: Hackly Magnetism: None Reaction with HCl: Weak Identification in hand sample:Colour and metallic characteristics are diagnostic. Associations:Found associated with mafic volcanic rocks, formed by reaction between Cu-bearing solutions and Fe-bearing minerals. Associated minerals are cuprite, chalcocite, bornite, epidote, calcite, chlorite and zeolites. Industrial / ecomonic uses:Used as electrical wire due to electrical conductivity and relatively low price. Comments:Obviously a source of copper, however most copper in modern times is mined from sulfide minerals.

  47. Native Elements Graphite (C) Hardness: 1 – 2 Streak: Black Density: 2.1 - 2.3 Lustre: Dull metallic, greasy feel Habit: Fine grained aggregateColours: Silver-black Crystal System: Hexagonal Cleavage: Perfect basal Fracture: Uneven Magnetism: None Reaction with HCl: None Identification in hand sample:Softness and lustre are best indicators. Associations:Common in pelitic metamorphic rocks such as phyllite, slate and schist. Produced as a result of decomposition of organic material. Industrial / ecomonic uses:Used in pencil leads and as a dry lubricant. Comments:Due to its softness, graphite is usually quite messy!

  48. Reference Cupit, Kerry. Mineral 1.0. 10June2011. Online. http://www.spaceman.ca/mineral/index.php

More Related