Silikatlar Descriptive Mineralogy II (oxyanion minerals) DESCRIPTIVE MINERALOGY II (OXYANION MINERALS) DESCRIPTIVE MINERALOGY II (OXYANION MINERALS) class of oxyanions --- cations with --- low ionic radius <0.6Å high ionic charge >3 --- small highly charged cations --- coordination with larger anion (e.g. O 2- ) --- firmly bonded groups (functional group or radical form)› tightly covalently bonded groups › single structural unit › central coordinating cation › in either 3-fold or 4-fold coordination vv triangular v tetrahedral › U 6+ › exception producing Linear coordination› oxyanion group of minerals › radicals Oxyanions CARBONATE [CO 3 ] 2- NITRATE [NO 3 ] 2- SULPHATE [SO 4 ] 2- CHROMATE [CrO 4 ] 2- MOLYBDATE [MoO 4 ] 2- TUNGSTATE [WO 4 ] 2- BORATE [B 3 O 4 (OH) 3 ] 2- PHOSPHATE [PO 4 ] 3- ARSENATE [AsO 4 ] 3- VANADATE [VO 4 ] 3- SILICATE [SiO 4 ] 4- URANYL [UO 2 ] 2+ carbonates, sulphates phosphates and silicates › the most important and widespread › rock forming mineralsCARBONATES CARBONATES › similar structure to NaCl › Na + › replaced by diavalent cations (Ca 2+ , Mg 2+ , Fe 2+ , Mn 2+ , Sr 2+ , Ba 2+ , Pb 2+ etc.) › Cl - › replaced by [CO 3 ] 2- › polyatomic triangular planar radical’s BUT › due to large ions present of carbonate minerals › cubic lattice › distorted to give structurally different carbonate groups The end members of carbonate group are:Hexagonal Carbonates (calcite group): Calcite (Cal) CaCO 3 Magnesite (Mag) MgCO 3 Siderite (Sid) FeCO 3 Rhodochrosite (Rhod) MnCO 3 Smithsonite (Smi) ZnCO 3 Dolomite (Dol) CaMg(CO 3 ) 2 Ankerite (Ank) CaFe(CO 3 ) 2 Orthorhombic Carbonates (aragonite group): Aragonite (Ara) CaCO 3 Witherite (Wit) BaCO 3 Strontianite (Str) SrCO 3 Cerussite (Cer) PbCO 3 Monoclinic Carbonates (others): Malachite (Mal) Cu 2 CO 3 (OH)y Azurite (Azu) Cu 3 (CO3) 2 (OH) 2Hexagonal Carbonates (calcite group): Calcite (Cal) CaCO 3 Magnesite (Mag) MgCO 3 Siderite (Sid) FeCO 3 Rhodochrosite (Rhod) MnCO 3 Smithsonite (Smi) ZnCO 3 Dolomite (Dol) CaMg(CO 3 ) 2 Ankerite (Ank) CaFe(CO 3 ) 2 Orthorhombic Carbonates (aragonite group): Aragonite (Ara) CaCO 3 Witherite (Wit) BaCO 3 Strontianite (Str) SrCO 3 Cerussite (Cer) PbCO 3 Monoclinic Carbonates (others): Malachite (Mal) Cu 2 CO 3 (OH)y Azurite (Azu) Cu 3 (CO3) 2 (OH) 2Hexagonal Carbonates (calcite group): Calcite (Cal) CaCO 3 Magnesite (Mag) MgCO 3 Siderite (Sid) FeCO 3 Rhodochrosite (Rhod) MnCO 3 Smithsonite (Smi) ZnCO 3 Dolomite (Dol) CaMg(CO 3 ) 2 Ankerite (Ank) CaFe(CO 3 ) 2 Orthorhombic Carbonates (aragonite group): Aragonite (Ara) CaCO 3 Witherite (Wit) BaCO 3 Strontianite (Str) SrCO 3 Cerussite (Cer) PbCO 3 Monoclinic Carbonates (others): Malachite (Mal) Cu 2 CO 3 (OH)y Azurite (Azu) Cu 3 (CO3) 2 (OH) 2Hexagonal Carbonates (calcite group): Calcite (Cal) CaCO 3 Magnesite (Mag) MgCO 3 Siderite (Sid) FeCO 3 Rhodochrosite (Rhod) MnCO 3 Smithsonite (Smi) ZnCO 3 Dolomite (Dol) CaMg(CO 3 ) 2 Ankerite (Ank) CaFe(CO 3 ) 2 Orthorhombic Carbonates (aragonite group): Aragonite (Ara) CaCO 3 Witherite (Wit) BaCO 3 Strontianite (Str) SrCO 3 Cerussite (Cer) PbCO 3 Monoclinic Carbonates (others): Malachite (Mal) Cu 2 CO 3 (OH)y Azurite (Azu) Cu 3 (CO3) 2 (OH) 2Hexagonal Carbonates (calcite group): Calcite (Cal) CaCO 3 Magnesite (Mag) MgCO 3 Siderite (Sid) FeCO 3 Rhodochrosite (Rhod) MnCO 3 Smithsonite (Smi) ZnCO 3 Dolomite (Dol) CaMg(CO 3 ) 2 Ankerite (Ank) CaFe(CO 3 ) 2 Orthorhombic Carbonates (aragonite group): Aragonite (Ara) CaCO 3 Witherite (Wit) BaCO 3 Strontianite (Str) SrCO 3 Cerussite (Cer) PbCO 3 Monoclinic Carbonates (others): Malachite (Mal) Cu 2 CO 3 (OH)y Azurite (Azu) Cu 3 (CO3) 2 (OH) 2Hexagonal Carbonates (calcite group): Calcite (Cal) CaCO 3 Magnesite (Mag) MgCO 3 Siderite (Sid) FeCO 3 Rhodochrosite (Rhod) MnCO 3 Smithsonite (Smi) ZnCO 3 Dolomite (Dol) CaMg(CO 3 ) 2 Ankerite (Ank) CaFe(CO 3 ) 2 Orthorhombic Carbonates (aragonite group): Aragonite (Ara) CaCO 3 Witherite (Wit) BaCO 3 Strontianite (Str) SrCO 3 Cerussite (Cer) PbCO 3 Monoclinic Carbonates (others): Malachite (Mal) Cu 2 CO 3 (OH)y Azurite (Azu) Cu 3 (CO3) 2 (OH) 2Hexagonal Carbonates (calcite group): Calcite (Cal) CaCO 3 Magnesite (Mag) MgCO 3 Siderite (Sid) FeCO 3 Rhodochrosite (Rhod) MnCO 3 Smithsonite (Smi) ZnCO 3 Dolomite (Dol) CaMg(CO 3 ) 2 Ankerite (Ank) CaFe(CO 3 ) 2 Orthorhombic Carbonates (aragonite group): Aragonite (Ara) CaCO 3 Witherite (Wit) BaCO 3 Strontianite (Str) SrCO 3 Cerussite (Cer) PbCO 3 Monoclinic Carbonates (others): Malachite (Mal) Cu 2 CO 3 (OH)y Azurite (Azu) Cu 3 (CO3) 2 (OH) 2Hexagonal Carbonates (calcite group): Calcite (Cal) CaCO 3 Magnesite (Mag) MgCO 3 Siderite (Sid) FeCO 3 Rhodochrosite (Rhod) MnCO 3 Smithsonite (Smi) ZnCO 3 Dolomite (Dol) CaMg(CO 3 ) 2 Ankerite (Ank) CaFe(CO 3 ) 2 Orthorhombic Carbonates (aragonite group): Aragonite (Ara) CaCO 3 Witherite (Wit) BaCO 3 Strontianite (Str) SrCO 3 Cerussite (Cer) PbCO 3 Monoclinic Carbonates (others): Malachite (Mal) Cu 2 CO 3 (OH)y Azurite (Azu) Cu 3 (CO3) 2 (OH) 2Hexagonal Carbonates (calcite group): Calcite (Cal) CaCO 3 Magnesite (Mag) MgCO 3 Siderite (Sid) FeCO 3 Rhodochrosite (Rhod) MnCO 3 Smithsonite (Smi) ZnCO 3 Dolomite (Dol) CaMg(CO 3 ) 2 Ankerite (Ank) CaFe(CO 3 ) 2 Orthorhombic Carbonates (aragonite group): Aragonite (Ara) CaCO 3 Witherite (Wit) BaCO 3 Strontianite (Str) SrCO 3 Cerussite (Cer) PbCO 3 Monoclinic Carbonates (others): Malachite (Mal) Cu 2 CO 3 (OH)y Azurite (Azu) Cu 3 (CO3) 2 (OH) 2Hexagonal Carbonates (calcite group): Calcite (Cal) CaCO 3 Magnesite (Mag) MgCO 3 Siderite (Sid) FeCO 3 Rhodochrosite (Rhod) MnCO 3 Smithsonite (Smi) ZnCO 3 Dolomite (Dol) CaMg(CO 3 ) 2 Ankerite (Ank) CaFe(CO 3 ) 2 Orthorhombic Carbonates (aragonite group): Aragonite (Ara) CaCO 3 Witherite (Wit) BaCO 3 Strontianite (Str) SrCO 3 Cerussite (Cer) PbCO 3 Monoclinic Carbonates (others): Malachite (Mal) Cu 2 CO 3 (OH)y Azurite (Azu) Cu 3 (CO3) 2 (OH) 2Hexagonal Carbonates (calcite group): Calcite (Cal) CaCO 3 Magnesite (Mag) MgCO 3 Siderite (Sid) FeCO 3 Rhodochrosite (Rhod) MnCO 3 Smithsonite (Smi) ZnCO 3 Dolomite (Dol) CaMg(CO 3 ) 2 Ankerite (Ank) CaFe(CO 3 ) 2 Orthorhombic Carbonates (aragonite group): Aragonite (Ara) CaCO 3 Witherite (Wit) BaCO 3 Strontianite (Str) SrCO 3 Cerussite (Cer) PbCO 3 Monoclinic Carbonates (others): Malachite (Mal) Cu 2 CO 3 (OH)y Azurite (Azu) Cu 3 (CO3) 2 (OH) 2CHARACTERISTIC PHYSICAL and CHEMICAL PROPERTIES CHARACTERISTIC PHYSICAL and CHEMICAL PROPERTIES Crystal Structure and Composition Crystal Structure and Composition Hexagonal Carbonates › rhombic lattice rhombic lattice › consists of consists of [ [CO CO 3 3 ] ] 2 2- - anions anions › equilateral triangle layers equilateral triangle layers ? ?r to c r to c- -axis alternating with layers of axis alternating with layers of cations cations in octahedral coordination with respect to oxygen of in octahedral coordination with respect to oxygen of [ [CO CO 3 3 ] ] 2 2- - e.g. calciteCrystal Structure and Composition Crystal Structure and Composition Orthorhombic Carbonates › large divalent cations › not permit 6-fold coordination but › 9-fold coordination with oxygen of [ [CO CO 3 3 ] ] 2 2- - groups e.g. aragonite Monoclinic Carbonates › structure › more complicated with presence of (OH) - groupsCrystal Structure and Composition Crystal Structure and Composition Orthorhombic Carbonates › large divalent cations › not permit 6-fold coordination but › 9-fold coordination with oxygen of [ [CO CO 3 3 ] ] 2 2- - groups e.g. aragonite Monoclinic Carbonates › structure › more complicated with presence of (OH) - groupsCrystal Structure and Composition Crystal Structure and Composition Hexagonal Carbonates › Cal › Ca › replaced by small amounts of Mg, Fe, Mn, Sr, Ba, Co, Zn › Mag › Mg › replaced by substantial Mn, very small amounts of Ni, Co › Sid › Fe › replaced by small amounts of Mn, Zn, Co › Rhod › Mn › replaced by small amount of Ca, Fe, Mg, Zn, Co, Cd › Smi › Zn › replaced by small amounts of Fe, Mn, Ca, Mg, Co, Cu › Dol › Mg › replaced by various amount of Ba, Co, Zn › Ca › replaced by Pb › Ank › Fe, Ca › replaced by various amounts of Mg, and Mn › solid soln › limited btw Dol-Ank › complete btw Mag-SidCrystal Structure and Composition Crystal Structure and Composition Orthorhombic Carbonates › Ara › Ca › replaced by appreciable amounts of Sr, Pb, Ba › very small amounts of Mg, Mn substitutes › Wit › Ba › replaced by small amounts of Ca, Sr, Mg › Str › Sr › replaced by small amounts of Ca, Ba › Cer › Cu › replaced by (?) Pb Hardness Hardness Hexagonal Carbonates H Cal =3.0;H Mag =3.5 ›5;H Sid =3.5 ›4; H Rho d=3.5 ›4.5;H Smi =4 ›5.5;H Dol =3.5 ›4; H Ank =3.5 Orthorhombic Carbonates H Ara =3.5 ›4;H Wit =3.0 ›3.75; H Str =3.5 ›4;H Cer =3.0 ›3.5 Monoclinic Carbonates H Mal =3.5 ›4; H Azu =3.5 ›4.Specific Gravity Specific Gravity Hexagonal Carbonates SG Cal =2.71;SG Mag =3.0 ›3.12;SG Sid =3.96 (pure); SG Rhod =3.5 ›3.7;SG Smi =4.30 ›4.45; SG Dol =2.8 ›2.9; SG Ank =2.95 ›3.1 Orthorhombic Carbonates SG Ara =2.94; SG Wit =4.27 ›4.35;SG Str =3.68 ›3.78;SG Cer =6.46 ›6.58 Monoclinic Carbonates SG Mal =3.9 ›4.03;SG Azu =3.77 ›3.89 Colour Colour Cal: colourless ›white, when impure gray, brown ›black, red, green, blue, violet, yellow Mag: white, gray, yellow, brown Sid: light ›dark brown, brownish red, ash-gray, greenish gray Rhod: rose-red, pink ›dark brown Smi: dirty brown ›gray, colourless ›white, green, blue or pink Dol: white, reddish, greenish white, rose-red, green, brown, gray, black Ank: white, gray, reddish Ara: colourless, white, pale yellow, violet Wit: colourless, gray, white Str: white, gray, yellow, apple-green, asparagus-green Cer: white, gray, grayish black, bleu, or green Mal: bright green Azu: azure-blue, Berlin-blue.Tenacity Tenacity Cal: brittle Mag: brittle Sid: brittle Rhod: brittle Smi: brittle Dol: brittle Ara: brittle Wit: brittle Str: brittle Cer: very brittle Mal: brittle Azu: brittle Luster Luster Cal: vitreous ›earthy Mag: vitreous ›silky Sid: vitreous ›pearly Rhod: vitreous ›pearly Smi: vitreous ›pearly Dol: vitreous ›pearly Ara: vitreous ›resinous Wit: vitreous ›resinous Str: vitreous ›resinous Cer: adamantine ›vitreous ›res. or pearly Mal: adam. ›vitreous, silky ›dull earthy Azu: vitreous ›sub-adamantine Streak Streak Cal: white ›grayish Sid: white Rhod: white Smi: white Dol: white Ara: white Wit: white Str: white Cer: white Mal: pale green Azu: pale blueCleavage Cleavage Cal: perfect Mag: perfect Sid: perfect Rhod: perfect Smi: perfect Dol: perfect Ara: distinct Wit: distinct Str: good Cer: distinct Mal: perfect Azu: perfect but interrupted Fracture Fracture Cal: conchoidal Mag: conchoidal Sid: uneven or sub-conchoidal Rhod: uneven Smi: uneven ›imperfectly conchoidal Dol: sub-conchoidal Ara: sub-conchoidal Wit: uneven Str: uneven Cer: conchoidal Azu: conchoidalOther Physical Properties Other Physical Properties Cal: twinning common, parting along twin lamellae: transparent ›translucent, reacts with dilute HCl Mag: transparent ›translucent, reacts with hot dilute HCl Sid: botryoidal, compact or earthy, transparent ›translucent Rhod: transparent ›sub-translucent, globular ›botryoidal Smi: reniform, botryoidal, stalagtitic, honeycombed masses (dry-bone ore) translucent Dol: transparent ›translucent Ara: acicular radiating groups, transparent ›translucent Wit: sub-transparent ›translucent Str: transparent ›translucent Cer: transparent ›sub-translucent Mal: acicular, massive, incrusting, transparent ›translucent Azu: transparent ›sub-translucentBORATES BORATES › over 100 borate minerals › most common ones Kernite (Ker) Na 2 B 4 O 6 (OH) 2 .3H 2 O Borax (Box) Na 2 B 4 O 5 (OH) 4 .8H 2 O Ulexite (Ule) NaCaB 5 O 6 (OH) 6 .5H 2 O Colemanite (Col) CaB 3 O 4 (OH) 3 .H 2 O CHARACTERISTIC PHYSICAL and CHEMICAL PROPERTIES CHARACTERISTIC PHYSICAL and CHEMICAL PROPERTIES Crystal Structure and Composition Crystal Structure and Composition › (BO 3 ) 3- or [BO 2 (OH) ] 2- triangular units › B 3+ › in 3-fold coordination › capable of polymerization similar to [SiO 4 ] 4- tetrahedral groups in silicates› B 3 + › also cap. of forming tetrahedral units (BO 4 ) 5- or [BO 3 (OH) ] 4- with 4-fold coord. › in Box [BO 3 (OH) ] tetrahedral and [BO 2 (OH) ] triangles › // to c-axis › where Na + is in 6-fold coordination with H 2 O mols producing [Na(H 2 O) 6 ] octahedra Hardness Hardness › low to moderate 1 ›4.5 H Ker =3; H Box =2 ›2.5;H Ule =1;H Col=4 ›4.5Specific Gravity Specific Gravity › low: 1.6 ›2.5 SG Ker =1.953;SG Box =1.69 ›1.72; SG Ule =1.65;SG Col =2.42 Colour Colour Ker: colourless ›white Box: white, grayish, bluish or greenish Ule: white Col: colourless ›milky white, yellowish white, gray. Streak Streak Ker: white; Box: white; Ule: white; Col: white Luster Luster Ker: vitreous ›pearly; Box: vitreous ›resinous, earthy; Ule: silky; Col: vitr. ›adam. Tenacity Tenacity Box: rather brittleCleavage Cleavage Ker: perfect; Box: perfect; Col: highly perfect. Fracture Fracture Box: conchoidal; Col: uneven ›sub-conchoidal. Other Physical Properties Other Physical Properties Ker: soluble in cold H2O, transparent Box: translucent ›opaque, sweetish alkaline taste Ule: fine silky fibers Col: short prismatic columnar crystals, transparent ›translucent.SULPHATES SULPHATES › large # of sulphate minerals › essentials Anhydrous Orthorhombic Sulphates: Anhydrite (Anh) CaSO 4 Barite (Bar) BaSO 4 Celestite (Cel) SrSO 4 Anglesite (Ang) PbSO 4 Hydrous Monoclinic Sulphate: Gypsum (Gyp) CaSO 4 .2H 2 OSULPHATES SULPHATES › large # of sulphate minerals › essentials Anhydrous Orthorhombic Sulphates: Anhydrite (Anh) CaSO 4 Barite (Bar) BaSO 4 Celestite (Cel) SrSO 4 Anglesite (Ang) PbSO 4 Hydrous Monoclinic Sulphate: Gypsum (Gyp) CaSO 4 .2H 2 OSULPHATES SULPHATES › large # of sulphate minerals › essentials Anhydrous Orthorhombic Sulphates: Anhydrite (Anh) CaSO 4 Barite (Bar) BaSO 4 Celestine (Cel) SrSO 4 Anglesite (Ang) PbSO 4 Hydrous Monoclinic Sulphate: Gypsum (Gyp) CaSO 4 .2H 2 OSULPHATES SULPHATES › large # of sulphate minerals › essentials Anhydrous Orthorhombic Sulphates: Anhydrite (Anh) CaSO 4 Barite (Bar) BaSO 4 Celestine (Cel) SrSO 4 Anglesite (Ang) PbSO 4 Hydrous Monoclinic Sulphate: Gypsum (Gyp) CaSO 4 .2H 2 OSULPHATES SULPHATES › large # of sulphate minerals › essentials Anhydrous Orthorhombic Sulphates: Anhydrite (Anh) CaSO 4 Barite (Bar) BaSO 4 Celestine (Cel) SrSO 4 Anglesite (Ang) PbSO 4 Hydrous Monoclinic Sulphate: Gypsum (Gyp) CaSO 4 .2H 2 OSULPHATES SULPHATES › large # of sulphate minerals › essentials Anhydrous Orthorhombic Sulphates: Anhydrite (Anh) CaSO 4 Barite (Bar) BaSO 4 Celestite (Cel) SrSO 4 Anglesite (Ang) PbSO 4 Hydrous Monoclinic Sulphate: Gypsum (Gyp) CaSO 4 .2H 2 OSULPHATES SULPHATES › large # of sulphate minerals › essentials Anhydrous Orthorhombic Sulphates: Anhydrite (Anh) CaSO 4 Barite (Bar) BaSO 4 Celestite (Cel) SrSO 4 Anglesite (Ang) PbSO 4 Hydrous Monoclinic Sulphate: Gypsum (Gyp) CaSO 4 .2H 2 O CHARACTERISTIC PHYSICAL and CHEMICAL PROPERTIES CHARACTERISTIC PHYSICAL and CHEMICAL PROPERTIES Crystal Structure and Composition Crystal Structure and Composition › anionic (SO 4 ) 2- groups › S › in tetrahedral coordination wrt O 2- with covalent bondsCrystal Structure and Composition Crystal Structure and Composition › in Bar and other orthorhombic sulphates › large Ba 2+ , Sr 2+ and Pb 2+ ions › coordinated to 12 O 2- ions belonging to 7 different (SO 4 ) groups In hydrous monoclinic sulphates Gyp Ca2+ is surrounded with nearest 6 O2- and 2H2O molecules with 8-fold coordination (FIG).Crystal Structure and Composition Crystal Structure and Composition › in hydrous monoclinic sulphates › Gyp › Ca 2+ › surrounded with nearest 6 O 2- and 2H 2 O molecules with 8-fold coordinationCrystal Structure and Composition Crystal Structure and Composition › Anh › Ca › replaced by small amounts of Sr and Ba › Bar › Ba › replaced by Sr, Pb, Ca, Hg, Co › Cel › Sr › replaced by Ba, Ca, Hg, Pb › Gyp › Ca › replaced by Mg, Si, Ti, Fe, Sr, B, Al, Mn, Cu, Li, Be, Y, Zr, Au, Ba and Bi occurs as traces Hardness Hardness › low › 1.5 ›3.5 H Anh =3 ›3.5;H Bar =2.5 ›3.5; H Cel =3 ›3.5;H Ang =2.75 ›3;H Gyp =1.5 ›2 Specific Gravity Specific Gravity SG Anh =2.899 ›2.985;SG Bar =4.3 ›4.6;SG Ce l=3.95 ›3.97; SG Ang =6.3 ›6.39; SG Gyp =2.314 ›2.328Colour Colour Anh: white with grayish, bluish, reddish tinge ›brick-red Bar: white, yellow, gray, blue, red, brown ›dark brown Cel: white, faint bluish, reddish Ang: white, tinged yellow, gray, green, blue Gyp: white, gray, flesh-red, honey-yellow, ocher-yellow, blue, brown ›black (impure) Streak Streak Anh: grayish white; Bar: white; Cel: white; Ang: white; Gyp: white. Luster Luster Anh: pearly ›greasy ›vitreous; Bar: vitreous ›resinous; Cel: vitreous ›pearly; Ang: highly adamantine ›resinous ›vitreous; Gyp: pearly shining ›sub-vitreous ›dull earthy. Tenacity Tenacity Anh: brittle; Bar: brittle; Ang: very brittle. Cleavage Cleavage Anh: perfect-rectangular; Bar: perfect-rectangular; Cel: perfect; Ang: distinct- interrupted; Gyp: eminentFracture Fracture Anhy: uneven ›splintery; Bar: uneven; Cel: uneven; Ang: conchoidal; Gyp: chonchoidal Other Physical Properties Other Physical Properties Anh: usually massive, granular and fibrous Bar: crystal, fibrous, lamellar, crested, granular, transparent ›translucent, fetid when rubbed Cel: tabular, prismatic crystals, fibrous, radiated, globular, granular, transparent ›sub- transparent Ang: tabular, prismatic crystals, massive, granular, stalagtitic, nodular transparent ›opaque Gyp: flattened, prismatic crystals, twinning common, transparent ›opaquePHOSPHATES PHOSPHATES › rare with exception of apatite › most common ones Apatite (Apa) Ca 5 (PO 4 ) 3 (F,Cl,OH) Pyromorphite (Pyrm) Pb 5 (PO 4 ) 3 Cl Amblygonite (Amb) LiAl(PO 4 )F Monazite (Mon) (Ce,La,Y,Th)PO 4 Triphyllite (Tri) Li(Fe, Mn)PO 4 CHARACTERISTIC PHYSICAL and CHEMICAL PROPERTIES CHARACTERISTIC PHYSICAL and CHEMICAL PROPERTIES Crystal Structure and Composition Crystal Structure and Composition › P 5+ › tetrahedral anionic (PO 4 ) 3- group with O 2- › in Apa › oxygen of (PO 4 ) groups › linked to Ca in two different structural sites › in one site, Ca › in irregular 9-fold coord. › in other site, Ca › in irregular 8-fold coord. › each F [or (OH) or Cl ] › lies in a triangle with three Ca› Prym › iso-structural with Apa › Amb structure › (AlO 6 ) octahedra and (PO 4 ) tetrahedra › Li › in 5-fold coord. and lies between (PO 4 ) tetrahedra and nearest Al octahedra › Mon › REE › in 9-fold coordination with O, linking 6 (PO 4 ) tetrahedra › Phosphate group › crystallizes in › Apa and Pyrm › hexagonal › Amb › triclinic › Mon › monoclinic › in Apa › F ?Cl ?(OH) ?(CO 3 ) substitution › Flour-Apa (Hydroxyl-Apa) › Chlor-Apa (Carbonate-Apa) › [PO 4 ] 3- › partially replaced by [SO 4 ] 2- and [SiO 4 ] 4- › P 5+ +Ca 2+ ?S 6+ +Na + › common › Ca › replaced by Mn and Sr › P 5+ › replaced by As 5+ and V 5+ › complete solid solution › btw Pyrm and Mim Pb 5 (AsO 4 ) 3 Cl › by [AsO 4 ] 3- ?[PO 4 ] 3- substitution › in Amb › Li › replaced by Na › due to F ?(OH) substitution › in Mon › [SiO 4 ]?[PO 4 ] substitutionHardness Hardness H Apa =5 ›4.5(when massive);H Pyrm =3.5 ›4;H Amb =6; HMon=5 ›5.5 Specific Gravity Specific Gravity SGApa=3.17 ›3.23;SG Pyrm=6.5 ›7.1; SGAmb=3.01 ›3.09;SG Mon=4.9 ›5.3. Colour Colour Apa: sea-green, bluish green, violet-blue, white, yellow, gray, red, flesh-red, brown Pyrm: green, yellow, brown, waxy yellow, orange-yellow, grayish white, milk-white Amb: white ›pale greenish, bluish, yellowish, grayish, brownish white Mon: hyacinth-red, clove-brown, reddish or yellowish brown Streak Streak Apa: white; Pyrm: white ›yellowish; Amb: white; Mon: white (?) Luster Luster Apa: vitreous ›sub-resin.; Pyrm: resin.; Amb: pearly ›vitreous › greasy; Mon: resin. Tenacity Tenacity Apa: brittle; Pyrm: brittle; Amb: brittle; Mon: brittleCleavage Cleavage Apa: imperfect, but parting is present; Pyrm: traces; Amb: perfect; Mon: perfect Fracture Fracture Apa: conchoidal ›uneven; Pyrm: subconchoidal ›uneven; Amb: uneven › sub- conchoidal; Mon: conchoidal ›uneven Other Physical Properties Other Physical Properties Apa: long prismatic, columnar crystals, also globular and reniform, massive cryptocrystalline variety Collophane, transparent ›opaque Pyrm: prismatic crystals, globular, reniform, botryoidal, fibrous, granular, sub- transparent ›sub-translucent Amb: large, coarse columnar crystals, massive, polysynthetic twins common, sub- transparent ›subtranslucent Mon: crystals very smallOTHER OXYANION MINERALS OTHER OXYANION MINERALS › very rare › important species of each group Chromates Crocoite (Cro) PbCrO 4 Tungstates Wolframite (Wolf) (Fe, Mn)WO 4 Scheelite (Sch) CaWO 4 Molybdates Wulfenite (Wul) PbMoO 4 Arsenates Erythrite (Ery) Co 3 (AsO 4 ) 2 .8H 2 O Annabergite (Ann) Ni 3 (AsO 4 ) 2 .8H 2 O Mimetite (Mim) Pb 5 (AsO 4 ) 3 Cl Vanadates Vanadinite (Van) Pb 5 (VO 4 ) 3 Cl Uranylates Torbenite (Tor) Ca(UO 2 ) 2 (PO 4 ) 2 .12H 2 OOTHER OXYANION MINERALS OTHER OXYANION MINERALS › very rare › important species of each group Chromates Crocoite (Cro) PbCrO 4 Tungstates Wolframite (Wolf) (Fe, Mn)WO 4 Scheelite (Sch) CaWO 4 Molybdates Wulfenite (Wul) PbMoO 4 Arsenates Erythrite (Ery) Co 3 (AsO 4 ) 2 .8H 2 O Annabergite (Ann) Ni 3 (AsO 4 ) 2 .8H 2 O Mimetite (Mim) Pb 5 (AsO 4 ) 3 Cl Vanadates Vanadinite (Van) Pb 5 (VO 4 ) 3 Cl Uranylates Torbenite (Tor) Ca(UO 2 ) 2 (PO 4 ) 2 .12H 2 OCHARACTERISTIC PHYSICAL and CHEMICAL PROPERTIES CHARACTERISTIC PHYSICAL and CHEMICAL PROPERTIES Crystal Structure and Composition Crystal Structure and Composition › Cro › iso-structural with Mon › Pb › 9-fold coordination with O, linking 6 [CrO 4 ] 2- tetrahedra › Wolf str. › distorted tetrahedral [WO 4 ] 2- groups and octahedral (Fe, Mn)O 6 groups › Sch str. › flattened [WO 4 ] 2- tetrahedra and CaO 8 polyhedra › Wul › iso-structural with Sch › Ery str › layered structure › strong bonds btw [AsO 4 ] 3- tetrahedra and Co(O,H 2 O) octahedra › str. of Mim and Van › iso-structural with Apa › Tor str. ›[ PO 4 ] 3- tetrahedra and [(UO 2 )O 4 ] 6- polyhedra producing [UO 2 PO 4 ] - corrugated layer that are held together by weak H-bonds to H 2 O mols› crystallization systems: Sch, Wul: tetragonal Van: hexagonal Tor: orthorhombic Cro, Wolf, Ery, Ann: monoclinic › solid solution series › in Wolf › Fe and Mn substitutes each other › Sch › W › replaced by Mo › Wul › Pb › replaced by Ca and Mo with W › Ery and Ann › complete solid solution series › Co › replaced by Ni › Mim › As › replaced by P, and Pb by Ca › Van › V › replaced by As and Pb by Ca, Zn, Cu Hardness Hardness H Cro =2.5 ›3; H Wolf =5 ›5.5; H Sch =4.5 ›5; H Wul =2.75 ›3; H Ery =1.5 ›2.5; H Ann =2.5 ›3; H Mim =3.5; H Van =2.75 ›3; H Tor =2 ›2.5 Specific Gravity Specific Gravity SG Cro =5.9 ›6.1;SG Wolf =7 ›7.5;SG Sch =5.9 ›6.1; SG Wul =6.7 ›7;SG Ery =2.95;SG Ann =3; SG Mim =7.0 ›7.25;SG Van =6.66 ›7.10;SG Tor =3.2Colour Colour Cro: bright hyacinth-red Wolf: dark grayish, brownish black Sch: white, yellowish white, pale yellow, brownish greenish, reddish Wul: wax- & orange-yellow, siskin- & olive-green, yellowish gray, grayish white, brown, orange ›bright red Ery: crimson- & peach-red Ann: apple-green; Mim: pale yellow ›brown, orange-yellow, white or colourless Van: deep ruby-red, light brownish yellow, straw-yellow, reddish brown Tor: emerald- & grass-green, leak- & apple- & siskin green Streak Streak Cro: orange-yellow Wolf: nearly black Sch: white Wul: white Ery: pale red Ann: pale green (?) Mim: white Van: white or yellowish Tor: pale greenLuster Luster Cro: adamantine ›vitreous; Wolf: submetallic; Sch: vitreous ›adamantine; Wul: resinous ›adamantine; Ery: pearly ›adamantine ›vitreous ›dull earthy; Mim: resinous; Van: resinous; Tor: pearly ›sub-adamantine Tenacity Tenacity Cro: sectile; Wolf: brittle; Sch: brittle; Wul: brittle; Ery: sectile; Ann: sectile (?); Mim: brittle; Van: brittle; Tor: brittle Cleavage Cleavage Cro: rather distinct; Wolf: very perfect; Sch: distinct-interrupted; Wul: very smooth; Ery: highly perfect; Ann: perfect; Mim: imperfect; Tor: perfect Fracture Fracture Cro: chonchoidal ›uneven; Wolf: uneven; Sch: uneven; Wul: sub-chonchoidal; Mim: uneven; Van: uneven ›flat chonchoidalOther Physical Properties Other Physical Properties Cro: prismatic crystals, granular, translucent Wolf: bladed, tabular, prismatic crystals, opaque Sch: octahedral, tabular crystals, reniform, granular, transparent ›translucent Wul: square-tabular, extremely thin crystals, granular, massive, sub-transparent ›sub- translucent Ery: prismatic crystals, reniform, drusy, stellate, transparent ›sub-translucent Ann: capillary crystals, massive, disseminated, fusible Mim: crystals prismatic, rounded barrel shaped forms, as branching groups, tapering down to a slender point, rounded to globular forms, in mammillary crusts, sub- transparent ›translucent Van: hexagonal prismatic crystals, sub-translucent ›opaque Tor: square tablets, very thin, micaceous, transparent ›sub-translucent