Silikatlar Desciptive Mineralogy DESCRIPTIVE MINERALOGY DESCRIPTIVE MINERALOGY basis of chem. comp. --- classification --- descriptive mineralogy --- because --- mins with same anion / anionic groups --- dominant in chem. comp. --- roughly similar physical, chemical, and optical properties --- mins of same group --- tend to occur together or --- in similar geological envs e.g. sulphides --- in close mutual assoc.in veins silicates --- great bulk of rocks of Earth’s crustClassification of the Minerals Non-Silicates – Native Elements – Halides – Sulfides –Oxides – Hydroxides – Carbonates – Sulfates – Phosphates Silicates – Orthosilicates – Sorosilicates – Cyclosilicates – Chain Silicates – Layer Silicates (phyllosilicates) – TectosilicatesNATIVE MINERALS NATIVE MINERALS - 20 elements --- in uncombined native state --- 3 groups --- native metals --- native semi-metals --- native non-metals NATIVE METALS --- 3 groups --- Gold Group: Au, Ag, Cu --- Platinum Group: Pt, Ir, Os --- Iron Group: Fe, Fe-Ni alloy (Kamacite & Taenite) --- also Hg, Ta, Sn and Zn --- as native elements in natureNATIVE METALS --- 3 groups --- Gold Group: Au, Ag, Cu --- Platinum Group: Pt, Ir, Os --- Iron Group: Fe, Fe-Ni alloy (Kamacite & Taenite) --- also Hg, Ta, Sn and Zn --- as native elements in nature Characteristic Physical and Chemical Properties X-structure and Composition --- in isometric (cubic) system --- all --- metallic bondingNATIVE METALS --- 3 groups --- Gold Group: Au, Ag, Cu --- Platinum Group: Pt, Ir, Os --- Iron Group: Fe, Fe-Ni alloy (Kamacite & Taenite) --- also Hg, Ta, Sn and Zn --- as native elements in nature Characteristic Physical and Chemical Properties X-structure and Composition --- in isometric (cubic) system --- all --- metallic bondingComplete solid solution --- btw Au-Ag (electrum) --- Cu, Fe, Bi, Pb, Sn, Zn, and Pt-group metal atoms --- in Au str --- frequently Au, Hg and Cu, rarely Pt, Sb, and Bi --- in Ag str --- btw Ag-Hg (amalgam) --- Cu --- small amounts of Ag, Bi, Hg, As, and Sb --- Pt-group --- Fe, Ir, Os, Rh, Pd, Cu, Au, and Ni --- Fe-group --- some Ni and frequently Co, Mn, S, and Cstreak --- Au --- yellow --- Ag --- white --- Cu --- red metallic-shining --- Pt --- white › steel-gray luster --- all --- metallic luster tenacity --- all --- malleable, ductile fracture --- all --- hackly fracture other physical properties --- Fe-group --- magnetic --- Pt-group --- magnetic property --- if Fe impurities --- all groups --- good conductor heat and electricity hardness --- Au-group --- H=2.5 ›3 --- Pt- and Fe-groups --- H=4 ›4.5 specific gravity --- very high --- SG Au =15 ›19.3 (pure) --- SG Ag =10.5 --- SG Cu =8.9 --- SG Pt =14 ›21.45 (pure) --- SG Fe =7.3 ›7.9. colour --- Au --- yellow ›paler with Ag content --- Ag --- white (tarnished to brown ›black) --- Cu --- red (tarnished dark brown) --- Pt --- steel-gray --- Fe --- steel-gray ›blackNATIVE SEMI-METALS --- As, Sb, and Bi --- very rare --- strong bonding btw 4 closest atoms --- forming pyramidal groups with covalent bonds --- as layers --- btw layers // to 0001 --- weak bonding resulting a good Cleavage --- Tenacity --- brittle --- poor conductors of electricity and heatNATIVE NON-METALS --- S and C --- very different X-str --- very different physical properties Characteristic Physical and Chemical Properties X-str and composition --- S --- orthorhombic system --- S atoms --- in ring of 8 atoms --- forming covalently bonded S8 molecule --- rings --- bonded to each other by van der Waals forces --- small amounts of Se substitution--- str of two C polymorphs --- different --- diamond --- cubic system --- strongly bonded by covalent bonds to 4 C neighbours in a tetrahedral coordination --- graphite --- hexagonal system --- 6-membered rings --- covalently bonded --- van der Waals bond btw sheets --- diamond --- pure C --- graphite --- impure, iron oxide, clay and other mineralshardness --- H S =1.5 ›2.5; H Dia =10; H Grap =1-2 specific gravity --- SG S =2.05 ›2.09; SG Dia =3.52; SG Grap =2.23 colour --- S --- yellow (with impurities ›green, gray, red) --- dia --- colourless ›pale shades of yellow, red, orange, green, blue, brown and grayish-black --- Grap --- black streak --- S: white, Grap: black luster --- S: resinous ›greasy; Dia: adamantine ›greasy (uncut); Grap: metallic ›earthy tenacity --- S: brittle; Dia: brittle; Grap: flexible cleavage --- S: imperfect; Dia: highly perfect; Grap: basal perfect fracture --- S: conchoidal; Dia: chonchoidal other physical properties --- S --- transparent ›translucent, poor conductor of heat, easily burn --- Dia --- strong dispersion (1 carat=200mg) --- Grap --- soils finger, greasy feelSULPHIDES SULPHIDES --- important group of ore minerals --- general formula ---- M m X nSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsSSULPHIDES SULPHIDES --- general formula ---- M m X n --- general order in decreasing ratio of M:X Chalcocite (Cit) Cu 2 S Bornite (Bo) Cu 5 FeS 4 Galena (Ga) PbS Sphalerite (Sph) ZnS Chalcopyrite (Cpy) CuFeS 2 Covellite (Cov) CuS Cinnabar (Cin) HgS Realgar (Re) AsS Pyrrotite (Pyrr) Fe 1-x S Orpiment (Orp) As 2 S 3 Stibnite (Sti) Sb 2 S 3 Pyrite (Py) FeS 2 Marcacite (Ma) FeS 2 Molybdenite (Mo) MoS 2 Arsenopyrite (Ars) FeAsS--- some of common sulphide compositions ---represented on S-Cu-Fe triangleCharacteristic Physical and Chemical Properties X-str and composition --- crystallize in different crystal systems Ga, Sph, Py in isometric system Bo, Cpy in tetragonal system Cov, Cin, Mo in hexagonal system Sti, Ma in orthorhombic system Cit, Re, Pyrr, Orp, Ars in monoclinic system --- ionic, covalent and metallic bonding characteristics --- minor and trace amounts of different elements --- str of sulphide mins Cit Ag, Au Ga Ag, Pt, Pd, Zn, Cd, Mo, Ni, Hg, Ga, Ge, In, Sn, Sb, As, Bi, Se, Te Sph Fe, Mn, Cd, Ga, Ge, In, Hg, Co, Cu, Ag, Sn Cpy Au, Ag, Pt, Pb, Co, Ni, Mn, Sn, Zn, As, Se Cin Se, Te Pyrr Ni, Co, Mn, Cu Orp Sb Sti Ag, Au, Fe, Pb, Cu Py Ni, Co, Au, Cu Ma Ag, Ti, V, Tl Ars Cohardness --- H --- from 1.5 ›4 for most sulphides with the exception of Py, Ma, and Ars e.g. H Sph =3.5 ›4; H Cpy =3.5 ›4; H Cov =1.5 ›2; H Cin =2.5 specific gravity --- from 3.4 ›8.1 e.g. SG Ga =7.4 ›7.6; SG Sph =3.9 ›4.1; SG Cpy =4.1 ›4.3 colour --- Cit: lead-gray (tarnished black) Bo: brownish-bronze (tarnished purple-blue) Ga: lead-gray Sph: colourless (pure) green, yellow, red (ruby zinc), brownish ›black streak --- Cit: grayish black Bo: grayish black Ga: lead-gray Sph: white ›yellow ›brown luster --- Most --- metallic luster (Bo: metallic; Ga: bright metallic) Sph: resinous ›sub-metallic ›adamantine; Re: resinous; Pyrr: metallic; Orp: resinous ›pearly tenacity --- Cpy: brittle; Cov: flexible; Re: sectile; Orp: flexible, sectile; Py: brittlecleavage --- Ga: perfect-cubic; Sph: perfect; Cov: perfect; Cin: perfect; Re: fair ›good; Ars: poor fracture --- Cit: conchoidal; Re: chonchoidal; Sti: sub-conchoidal, Py: conchoidal other physical properties --- Sph, Cin: transparent ›translucent --- Cpy: usually massive --- Re: association with Orp --- Orp: translucent, foliated --- Pyrr: magnetic, massive --- Sti: radiating group or bladed crystal, striations, easily fusible (candle-flame) --- Py: well-developed cubic system crystal --- Mo: scaly, greasy feelOXIDES OXIDES --- important group of ore mins --- also as minor or accessory mins in rocksOXIDES OXIDES --- important group of ore mins --- also as minor or accessory mins in rocks --- classified --- acc. to str into cubic-, tetragonal-, rhombohedral-oxides, and spinel gr. tetragonal oxides Rutile (Ru) TiO 2 Pyrolusite (Pyrl) MnO 2 Cassiterite (Cas) SnO 2 rhombohedral oxides Corundum (Cor) Al 2 O 3 Hematite (Hm) Fe 2 O 3 Ilmenite (Ilm) FeTiO 3 Geikielite MgTiO 3 Pyrophanite MnTiO 3OXIDES OXIDES --- important group of ore mins --- also as minor or accessory mins in rocks --- classified --- acc. to str into cubic-, tetragonal-, rhombohedral-oxides, and spinel gr. tetragonal oxides Rutile (Ru) TiO 2 Pyrolusite (Pyrl) MnO 2 Cassiterite (Cas) SnO 2 rhombohedral oxides Corundum (Cor) Al 2 O 3 Hematite (Hm) Fe 2 O 3 Ilmenite (Ilm) FeTiO 3 Geikielite MgTiO 3 Pyrophanite MnTiO 3OXIDES OXIDES --- important group of ore mins --- also as minor or accessory mins in rocks --- classified --- acc. to str into cubic-, tetragonal-, rhombohedral-oxides, and spinel gr. tetragonal oxides Rutile (Ru) TiO 2 Pyrolusite (Pyrl) MnO 2 Cassiterite (Cas) SnO 2 rhombohedral oxides Corundum (Cor) Al 2 O 3 Hematite (Hm) Fe 2 O 3 Ilmenite (Ilm) FeTiO 3 Geikielite MgTiO 3 Pyrophanite MnTiO 3OXIDES OXIDES --- important group of ore mins --- also as minor or accessory mins in rocks --- classified --- acc. to str into cubic-, tetragonal-, rhombohedral-oxides, and spinel gr. tetragonal oxides Rutile (Ru) TiO 2 Pyrolusite (Pyrl) MnO 2 Cassiterite (Cas) SnO 2 rhombohedral oxides Corundum (Cor) Al 2 O 3 Hematite (Hm) Fe 2 O 3 Ilmenite (Ilm) FeTiO 3 Geikielite MgTiO 3 Pyrophanite MnTiO 3OXIDES OXIDES --- important group of ore mins --- also as minor or accessory mins in rocks --- classified --- acc. to str into cubic-, tetragonal-, rhombohedral-oxides, and spinel gr. tetragonal oxides Rutile (Ru) TiO 2 Pyrolusite (Pyrl) MnO 2 Cassiterite (Cas) SnO 2 rhombohedral oxides Corundum (Cor) Al 2 O 3 Hematite (Hm) Fe 2 O 3 Ilmenite (Ilm) FeTiO 3 Geikielite MgTiO 3 Pyrophanite MnTiO 3OXIDES OXIDES --- important group of ore mins --- also as minor or accessory mins in rocks --- classified --- acc. to str into cubic-, tetragonal-, rhombohedral-oxides, and spinel gr. tetragonal oxides Rutile (Ru) TiO 2 Pyrolusite (Pyrl) MnO 2 Cassiterite (Cas) SnO 2 rhombohedral oxides Corundum (Cor) Al 2 O 3 Hematite (Hm) Fe 2 O 3 Ilmenite (Ilm) FeTiO 3 Geikielite MgTiO 3 Pyrophanite MnTiO 3OXIDES OXIDES --- important group of ore mins --- also as minor or accessory mins in rocks --- classified --- acc. to str into cubic-, tetragonal-, rhombohedral-oxides, and spinel gr. tetragonal oxides Rutile (Ru) TiO 2 Pyrolusite (Pyrl) MnO 2 Cassiterite (Cas) SnO 2 rhombohedral oxides Corundum (Cor) Al 2 O 3 Hematite (Hm) Fe 2 O 3 Ilmenite (Ilm) FeTiO 3 Geikielite MgTiO 3 Pyrophanite MnTiO 3OXIDES OXIDES --- important group of ore mins --- also as minor or accessory mins in rocks --- classified --- acc. to str into cubic-, tetragonal-, rhombohedral-oxides, and spinel gr. tetragonal oxides Rutile (Ru) TiO 2 Pyrolusite (Pyrl) MnO 2 Cassiterite (Cas) SnO 2 rhombohedral oxides Corundum (Cor) Al 2 O 3 Hematite (Hm) Fe 2 O 3 Ilmenite (Ilm) FeTiO 3 Geikielite MgTiO 3 Pyrophanite MnTiO 3OXIDES OXIDES --- important group of ore mins --- also as minor or accessory mins in rocks --- classified --- acc. to str into cubic-, tetragonal-, rhombohedral-oxides, and spinel gr. tetragonal oxides Rutile (Ru) TiO 2 Pyrolusite (Pyrl) MnO 2 Cassiterite (Cas) SnO 2 rhombohedral oxides Corundum (Cor) Al 2 O 3 Hematite (Hm) Fe 2 O 3 Ilmenite (Ilm) FeTiO 3 Geikielite MgTiO 3 Pyrophanite MnTiO 3spinels (AB 2 O 4 ) Al-Spinels A-site B-site Hercynite Fe 2+ Al 3+ Spinel (Sp) Mg 2+ Al 3+ Gahnite Zn 2+ Al 3+ Galaxite Mn 2+ Al 3+ Al 3+ Mn 2+ Cr-Spinels A-site B-site Chromite (Chro) Fe 2+ Cr 3+ Magnesiochromite Mg 2+ Cr 3+ Fe-Spinels A-site B-site Magnetite (Mt) Fe 3+ Fe 2+ Fe 3+ Magnesioferrite Mg 2+ Fe 3+ Fe 3+ Mg 2+ Franklinite Zn 2+ Fe 3+ Jacobsite Mn 2+ Fe 3+ Fe 3+ Mn 2+ Trevorite Fe 3+ Fe 3+ Ni 2+ Ti-Spinels A-site B-site Ulvospinel Fe 2+ Fe 2+ Ti 4+ Quandilite Mg 2+ Mg 2+ Ti 4+Characteristic Physical and Chemical Properties X-str and Composition --- in cubic oxides --- each cation --- surrounded by 6 O 2- --- MO 6 octahedra share all their edges with neighbouring octahedraCharacteristic Physical and Chemical Properties X-str and Composition --- in cubic oxides --- each cation --- surrounded by 6 O 2- --- MO 6 octahedra share all their edges with neighbouring octahedra--- tetragonal oxides --- rutile-structure --- each cation 4+ --- surrounded by 6 O 2- --- MO 6 octahedra share all their edges and corners with neighbouring octahedra so that each O 2- is surrounded by 3 cations --- in rhombohedral oxides --- str --- octahedral layers of edge sharing MO 6 --- hexagonal close packed O 2- array --- in spinels str --- cubic close packed O 2- with tetrahedral (A-sites) and octahedral (B-sites) sites occupied by cations--- cubic oxides --- peroskvite and magnesiowüstite --- a SSS with Mg ?Fe (Zn and ?Mn subs partly for Mg) --- tetragonal oxides rutile --- considerable Fe 2+ , Fe 3+ , Nb, Ta, Sn --- small Cr and V --- rhombohedral oxides --- very limited solid solution btw Hm and Cor with Al 3+ ?Fe 3+ --- solid solution btw --- Ilm-Hm --- limited --- Ulvospinel-Mt --- completehardness --- Cubic oxides --- H Per =5.5 ›6 --- Tetragonal oxides --- H Ru =6 ›6.5; H Pyrl =2 ›2.5; H Cas =6 ›7 --- Rhomb. oxides --- H Cor =9; H Hm =5.5 ›6.5; H Mt =5.5 ›6.5H Ilm =5.5 ›6; --- Spinels --- H Sp =8 specific gravity --- Cubic oxides --- SG Per =3.56 ›3.68; --- Tetragonal oxides --- SG Ru =4.18 ›4.25; SG Cas =6.8 ›7.1 --- Rhombohedral oxides --- SG Cor =3.95 ›4.1; SG Hm =4.9 ›5.3; SG Ilm =4.7 ›5 --- Spinels --- SG Sp =3.5 ›4.1; SG Chr =4.1 ›4.9; SG Mt =5.18 colour --- Cubic oxides --- Per: grayish white ›yellow brown --- Tetragonal oxides --- Ru: red ›reddish brown ›black --- Rhombohedral oxides --- Cor: colourless ›shades of brown, pink, blue Hm: reddish ›brown-black; Ilm: iron-black; --- Spinels --- Sp: white, red (ruby spinel), lavender, blue, green, brown, black Chr: iron-black ›brownish black Mt: iron-black streak --- Tetragonal oxides --- Ru: pale brown; --- Rhombohedral oxides --- Cor: uncoloured; Hm: light ›dark cherry-red --- Spinels --- Sp: white; Chr: dark brown; Mt: blackluster --- Tetragonal oxides --- Ru: adamantine ›metallic Cas: adamantine ›sub-metallic ›dull --- Rhombohedral oxides --- Cor: adamantine ›vitreous; Hm: metallic ›dull --- Spinels --- Sp: vitr › dull; Chr: metallic ›sub-metallic; Mt: metallic ›sub-metallic tenacity --- Tetragonal oxides --- Ru: brittle --- Rhombohedral oxides --- Cor: very tough, brittle Hm: brittle, elastic in thin lamina --- Spinels --- Sp: brittle; Chr: brittle; Mt: brittle cleavage --- Cubic oxides --- Per: perfect --- Tetragonal oxides --- Ru: distinct; Cas: imperfect --- Rhombohedral oxides --- Cor, Hm: no cleavage, well developed parting --- Spinels --- Sp: imperfect; Mt: not distinct fracture --- Tetragonal oxides --- Ru, Cas: sub-conchoidal ›uneven; --- Rhombohedral oxides --- Cor: uneven ›conchoidal; Hm: sub-conchoidal ›uneven --- Spinels --- Sp: conchoidal; Chr: uneven; Mt: hacklyother physical properties --- Cubic oxides --- Per: soluble in dil. HCl --- Tetragonal oxides --- Ru: sub-translucent ›transparent Pyrl: soils fingers, granular massive also dendritic habit Cas: radiating fibrous variety ›translucent, poor heat cond. --- Rhombohedral oxides --- Cor: feels cold, transparent ›translucent, barrel shaped X’s Hm: bothroidal; Ilm: may be magnetic --- Spinels --- Sp: translucent ›transparent ›opaque, octahedral crystal form Chr: translucent ›opaque, commonly massive, assoc. with yel.-green serp. Mt: strongly magneticHYDROXIDES HYDROXIDES Brucite Group Brucite (Bru) Mg(OH) 2 Manganite (Man) MnO(OH) Goethite Group Diaspore (Dias) ? AlO(OH) Goethite (Goe) ? FeO(OH) Bauxite Mineral Group Gibbsite (Gib) Al(OH) 3 Boehmite (Boeh) ? AlO(OH) Lepidochrocite (Lepi) ? FeO(OH) Amorphous Hydroxides Limonite (Lim) FeO(OH). nH 2 O Psilomelane (Psi) Mn oxide/hydroxideHYDROXIDES HYDROXIDES Brucite Group Brucite (Bru) Mg(OH) 2 Manganite (Man) MnO(OH) Goethite Group Diaspore (Dias) ? AlO(OH) Goethite (Goe) ? FeO(OH) Bauxite Mineral Group Gibbsite (Gib) Al(OH) 3 Boehmite (Boeh) ? AlO(OH) Lepidochrocite (Lepi) ? FeO(OH) Amorphous Hydroxides Limonite (Lim) FeO(OH). nH 2 O Psilomelane (Psi) Mn oxide/hydroxideCharacteristic Physical and Chemical Properties X-str and composition --- str --- characterized by (OH) - group or H 2 O molecules with weak hydrogen bonding --- Lim and Psi --- no definite str --- due to amorphous str --- in Bru --- Fe, Mn, and Zn subs for Mg --- in Dias --- Fe 3+ and Mn subs for Al --- in Goe --- Mn subs for Fe --- in Gib --- Fe 3+ subs for Al --- in Boeh --- Fe 3+ subs for Al --- in Lepi --- Mn 3+ subs for Fe 3+ --- Lim and Psi --- variable H 2 O content --- impurities of colloidal silica, phosphates, clay minerals and organic decomposition products, small amounts of hydrous Al 2 O 3 --- in Psi --- small amounts of Mg, Ca, Ni, Co, Cu --- also be present hardness --- H Bru =2.5; H Dias =6.5 ›7; H Goe =5 ›5.5; H Gib =2.5 ›3.5; H Boeh =3.5 ›4; H Lepi =5; H Lim =5 ›5.5; H psi =5 ›7 specific gravity --- SG Br =2.38 ›2.4; SG Dias =3.35 ›3.50; SG Goe =4.37 ›3.3 (impure) SG Gib =2.3 ›2.4; SG Boeh =3; SG Lepi =4.09; SG Lim =3.6 ›4; SG Psi =3.3 ›4.7colour --- Bru: white, gray, light green --- Dias: white, gray, yellowish, greenish --- Goe: yellowish brown › dark brown streak --- Goe: yellowish brown, ocher-yellow --- Lepi: orange --- Lim: yellowish brown --- Psi: brownish black luster --- Bru: pearly ›vitreous ›waxy --- Dias: vitreous ›brilliant ›pearly on cleavage --- Goe: adamantine ›dull, silky when fibrous --- Gib: pearly ›vitreous --- Lim: dull earthy ›silky tenacity --- Bru: flexible, sectile; Dias: very brittle cleavage --- Bru, Dias, Goe, Lepi: perfect; --- Boeh: good fracture --- Dias: chonchoidal other physical properties --- Bru: transparent ›translucent --- Dias: bladed, scaly and foliated habit, transparent ›sub-translucent --- Gib: translucent, spheroidal concretions, stalactitic, mammillary habit --- Lim, Psi: stalactitic, reniform, botryoidal, mammillary, concretionary habit, earthyHALIDES HALIDES --- characterized by dominance of electronegative halogen anions: F - , Cl - , Br - , I - e.g. Halite (Ha) NaCl Sylvite (Syl) KCl Fluorite (Flu) CaF 2 Characteristic Physical and Chemical Properties X-str and composition --- Ha str --- each cation and anion --- surrounded with 6 closest neighbours, in octahedral coordination --- Syl str--- similar structure where Na + --- replaced with K + cations--- Flu str --- Ca 2+ cations --- arranged at the corner --- face centers of cubic unit cell --- F - anions --- tetrahedrally coordinated to 4 Ca 2+ --- each Ca 2+ --- coordinated to 8 F - surrounding it at corners of a cube --- Ha-Syl --- isomorphous but little solid solution btw them --- both --- small amounts of Br replacing Cl --- impurities of clay minerals, iron oxide, Gyp and other evaporite minerals --- in Flu --- Y and Ce replaces Ca --- dark purple Flu --- appreciable amounts of Srhardness --- from 2 ›4, H Ha =2.5; H Syl =2.0; H Flu =4 specific gravity --- from 2 ›3.5, SG Ha =2.16 (pure) ›2.6; SG Syl =1.99; SG Flu =3.01 ›3.25 colour --- Ha: colourlees, white (pure), yellow, red, blue, purple (with impurities) --- Syl: colourlees and white (pure), yellowish red, bluish (with impurities) --- Flu: white, yellow, wine-yellow, green, greenish blue, violet-blue, sky-blue, rose- and crimson-red, brown luster --- vitreous luster tenacity --- brittle cleavage --- Ha and Syl: perfect-cubic; Flu: highly perfect-octahedral fracture --- Ha: conchoidal; Syl: uneven, Flu: flat-chonchoidal other physical properties --- Ha: usually cubic crystals, salty taste, soluble in H 2 O, transparent ›translucent --- Syl: salty but bitter taste, soluble in H 2 O, translucent --- Flu: cubic crystal forms or massive, transparent ›sub-translucent