Mineralname Chemical formula Melting point Crystal Crystal Class Space Group Unit cell Formula units Frequent crystal Twinning MoHs Hardness Density [g/cm3] Cleavage Fracture / Color Streak Transparency Lustre Optical cHaracter Refractive index Birefringence δ PleocHroism Doping [%] OtHer Piezoelectric crystals [°C] system (Symbol) surfaces Tenacity frequency constants; K (relative L=longitudin elastic electromech. temperature thermal dielectric piezoelectric piezoelectric al mode, compliance Coupling frequency frequency SAW M, degr. termal expansation constant) = charge voltage young's T=thickness [10^(-12) factor (BAW) spacing Δf coefficient velocity V(ef) K^2(emc) a(2) [10^(- T(T0) (Temp. (Power Flow conductivity coefficient Chemischer Name a [Å] b [Å] c [Å] T(rt) [°C] T(c) [°C] K(33) T Loss [%] Ec [kV/cm] d(33) [pm/V] k(33) k(t) N(33) [Hzm] N(t) [Hzm] Q(m) ε(T33)/ε(0) constant constant modulus mode m^2/N] K^2(emc) [%] [%] [*10^(-6) / °C] [m/s] (SAW) [%] 8)/°C ^2] Coeff.) [°C] Angle) [W/m/K] [(10^(-5))/K] pale to bright yellow, hexagonal-dipyramidal {10-10}, {0001}, {10-11}, yellowish transparent to resinous to diamond- nω=2.147; Mimetesite Pb5(AsO4)3Cl hexagonal P 6_3/m 10.211 10.211 7.418 Z=2 rare on {11-22} 3.8 - 4 ~7:2 imperfect on [10-11] conchoidal, brittle white uniaxial (-) 0.019 weak (6/m) {11-21}, {21-31} brown, yellow- translucent like nε=2.128 orange, white, Lead Arseno Chloride colorless nearly opaque, dihexagonal- lamellae flexible, black, lead- Molybdenite MoS2 1750 hexagonal P 6_3/mmc 3.16 3.16 12.32 Z=2 1 - 1.5 4.7 - 4.8 perfect on [0001] bluish gray translucent when metallic very strong dipyramidal (6/mmm) not elastic silvery gray Molybdenium di sulfide in thin flakes orthorhombic- {110}, {120} combinated nα=~1.640; orthorhom good on {001}, clear on brittle to yellow to yellow- transparent to Olivine (Mg,Fe)2SiO4 dipyramidal (2/m 2/m P bnm 6.01 4.78 10.30 Z=4 with {021}, {101}, {111} 6.5 - 7 3.2 - 4.5 white vitreous biaxial (+) nβ=~1.660; 0.040 bic {010} conchoidal green translucent 2/m) and {010} nγ=~1.680 Magnesium Iron Silicate brownish red, dark brown, nα=1.530-1.573; tough, flexible thin transparent to pearly, slightly metallic Phlogopite KMg3(AlSi3O10)(F,OH)2 monoclinicmonoclinic-prismatic (2/m) C2/m 3.16 3.16 12.30 Z=2 {001} composition twinning 2 - 2.5 2.75 - 2.97 perfect on (001) (basal) yellowish white biaxial (-) nβ=1.557-1.617; 0.028-0.045 fluorescent laminae translucent on cleavage surfaces brown, green, nγ=1.558-1.618 white dihexagonal- clear on {0001} and {11- yellowish PyrrHotHin FeS - Fe10S11 hexagonal dipyramidal (6/m 2/m P 6_3/mmc 3.44 3.44 5.88 Z=2 3.5 - 4.5 4.6 conchoidal, brittle gray to black opaque metallic 20} brown Iron Sulfide Hexagonal 2/m) pale brass- cubic- brittle, uneven, yellow penetration and greenish- to brownish- Pyrite FeS2 cubic disdodecahedron (2/m P a-3 5.42 5.42 5.42 Z=4 6 - 6.5 4.8 - 5 indistinct on {001} sometimes reflective, opaque metallic paramagnetic contact twinning black -3) conchoidal tarnishes Iron Sulfide Cubic darker dark green to green, yellow, yellow-orange, reddish- hexagonal-dipyramidal {10-10}, {0001}, {10-11}, brittle, uneven to transparent to resinous to nω=2.058; PyromorpHite Pb5(PO4)3Cl hexagonal P 6_3/m 9.97 9.97 7.32 Z=2 rarely on {11-22} 3.5 - 4 6.7 - 7 imperfect on [10-11] orange, yellow- white uniaxial (-) 0.010 weak (6/m) {20-21}, {11-21} conchoidal translucent subadamantine nε=2.048 brown to brown, tan, grayish to Lead Phosphoro Chloride colorless pink to rose- red, cherry-red, ditrigonal- on {01-12} (contact transparent to nω=1.814-1.816; RhodocHrosite Mn(CO3) trigonal R-3c 4.74 4.74 15.51 Z=6 3.5 - 4.5 3.3 - 3.6 perfect on {10-11} conchoidal yellow to white vitreous to pearly uniaxial (-) 0.218 weak scalenohedral (-3 2/m) and lamellar) translucent nε=1.596 yellowish gray, Manganese Carbonite brown on [001] colorless to pseudorhomohedral nα=1.507-1.513; perfect on {110} and {1- white, pink, transparent to vitreous, silky when pyroelectric and Scolecite (CaAl2Si3O10)*3H2O monoclinic monoclinic-domatic (m) Cc 18.51 18.97 6.53 Z=8 {010}, {110}, {111} contact- and 5 - 5.5 ~2.3 uneven, brittle white biaxial (-) nβ=1.516-1.520; 0.010 10} salmon, red or translucent fibrous piezoelectric penetration twinning, nγ=1.517-1.521 Calcium Aluminium Silicate green (Zeolite) on {010} lamellar colorless to nα=1.648-1.661; often monoclinic-prismatic uneven to grayish-white, transparent to vitreous, pearly on Spodumene LiAl(SiO3)2 monoclinic C2/c 9.52 8.32 5.25 Z=4 {100}, {010}, {110} common on {100} 6.5 - 7 3.1 - 3.2 perfect on {110} white biaxial (+) nβ=1.655-1.670; 0.014 - 0.018 strong fluorescent (2/m) conchoidal rose to violett, translucent cleavage surfaces nγ=1.662-1.670 (kunzite) Lithium Aluminium Silicate green colorless nα=1.484-1.500; [Na9-1,Ca0- monoclinic-prismatic common on {001} uneven to transparent to vitreous, pearly on Stilbite monoclinic C2/m 13.63 18.17 11.31 Z=4 3.5 - 4 2.1 - 2.2 perfect on {010} (usually), white, white biaxial (-) nβ=1.492-1.507; Potassium Calcium silicate 4(Si27Al9)O72]*28(H2O) (2/m) (penetration twinning) conchoidal translucent cleavage surfaces Aluminate pink nγ=1.494-1.513 brittle, flexible and monoclinic-prismatic common on {011} elastic in thin steel-gray, iron- opaque, thin Tenorite CuO 1326 monoclinic C2/c 4.67 3.42 5.12 Z=4 3.5 - 4 6 - 6.5 poor to indistinct brownish-black metallic to earthy biaxial (+) distinct (2/m) (lamellar) flakes; uneven to gray, black flakes transparent Copper (II) oxide conchoidal yellowish orthorhombic- brown nα=1.606-1.629; orthorhom uneven to transparent to Topaz Al2[(F,OH)2SiO4] dipyramidal (2/m 2/m P bnm 4.65 8.80 8.40 Z=4 8 3.5 - 3.6 perfect on (001) (common), white vitreous biaxial (+) nβ=1.609-1.631; 0.010 weak bic conchoidal translucent Aluminium Hydroxy Flouro 2/m) blau, violett, nγ=1.616-1.638 Silicate red, colorless black (common), colorless to brown, red, (Ca,K,Na)(Al,Fe,Li,Mg,Mn) orange, yellow, ditrigonal-pyramidal brittle, uneven, translucent to vitreous, sometimes nω=1.635-1.675; Tourmaline 3(Al,Cr,Fe,V)6(BO3)3(Si,Al trigonal R3m 15.84 - 16.03 15.84 - 16.03 7.10 - 7.15 Z=3 7 - 7.5 2.82 - 3.32 indistinct green, blue, white uniaxial (-) 0.018 - 0.040 moderate to strong (3m) small conchoidal opaque resinous nε=1.610-1.650 ,B)6O18(OH,F)4 violet, pink, can be bi- colored or even tri-colored in between red to reddish- Tausonite (Strontium hexoctahedral (4/m -3 translucent to SrTiO3 cubic P m3m 3.9 3.9 3.9 Z=1 6 - 6.5 ~4.8 indistinct brittle, conchoidal brown, orange, adamantine isotropic n=2.4 Titanate) 2/m) opaque dark gray yellow, orange, opaque to hexagonal-dipyramidal {0001}, {10-10}, {10-11}, uneven, white to bright yellowish- nω=2.416; Vanadinite Pb5(VO4)3Cl hexagonal P 6_3/m 10.32 10.32 7.34 Z=2 3 - 4 6.8 - 7.1 none brown, transparent or resinous to adamantine uniaxial (-) 0.066 (6/m) {21-31} conchoidal brown nε=2.350 sometimes red translucent Lead Vanadium Chloride brittle, in thin {10-11}, {10-12}, {0001}, penetration and metallic-gray, ditrigonal- flakes elastic, nω=3.150-3.220; Hematite Fe2O3 1539 - 1569 trigonal R-3c 5.04 5.04 13.77 Z=6 {10-18}, {11-23}, {01-14}, lamellar on {0001}, 5.5 - 6.5 5.2 - 5.3 none dull to bright bright red to dark red opaque metallic to splendent uniaxial (-) 0.280 moderate to strong scalenohedral (-3 2/m) uneven to nε=2.870-2.940 {01-11}, {11-20} {10-12} and {10-12} red Iron (III )Oxide conchoidal on {101}; reddish-brown, ditetragonal- polysynthetic twins on perfect on {110} and conchoidal to yellow, blue, transparent to nω=1.925-1.961; radioactive, Zircon ZrSiO4 2550 tetragonal dipyramidal (4/m 2/m I4_1/amd 6.59 6.59 5.94 Z=4 {100}, {110}, {101} {112} (shocked 7.5 4.67 white vitreous to adamantine uniaxial (+) 0.047 - 0.055 weak {111} uneven green, gray, opaque nε=1.980-2.015 fluorescent 2/m) crystals by meteorite colorless Zirconium Silicate impact) monoclinic-prismatic polysynthetic twins on AcantHite Ag2S 825 monoclinic P 2_1/n 4.23 6.93 7.86 Z=4 2.0 - 2.5 7.3 indistinct uneven iron-black black opaque metallic Silver sulfide monoclinic (2/m) {111} black, reddish ditetragonal- often prismatic with {110} perfect on {001} and brittle to weakly to yellowish transparent to nω=2.561; Anatase TiO2 tetragonal dipyramidal (4/m 2/m I4_1/amd 3.78 3.78 9.51 Z=4 rare on {112} 5.5 - 6 3.9 pale yellowish to white metallic to adamantine uniaxial (-) 0.073 weak and {010} {011} conchoidal brown, dark opaque nε=2.488 2/m) Titanium Oxide Anatase type blue, gray orthorhombic- pink, violet, nα=1.629-1.640; orthorhom brittle to transparent to Andalusite Al2SiO5 dipyramidal (2/m 2/m P nnm 7.78 7.92 5.57 Z=4 {110}, {001} rare on {101} 6.5 - 7.5 3.13 - 3.16 perfect on {110} yellow, green, white vitreous biaxial (-) nβ=1.633-1.644; 0.009 - 0.010 strongly trichroic bic subconchoidal nearly opaque Aluminium Silicate 2/m) white, gray nγ=1.638-1.650 usually green, colorless, hexagonal-dipyramidal brittle to transparent to nω=1.631-1.675; Apatite Ca5(PO4)3(F,Cl,OH) hexagonal P 6_3/m 9.38 9.38 6.86 Z=2 {10-10}, {0001}, {10-11} 5 3.2 indistinct yellow, blue, white vitreous to subresinous uniaxial (-) 0.004 - 0.014 weak to very weak (6/m) conchoidal translucent nε=1.627-1.668 violet, pink, Calcium Phosphate brown white, red, often on {110} orthorhombic- yellow, orange, vitreous, resinous on nα=1.529-1.530; orthorhom cyclically and imperfect on {110} and translucent to Aragonite CaCO3 dipyramidal (2/m 2/m P mcn 4.96 7.97 5.74 Z=4 3.5 - 4 2.94 brittle, conchoidal green, purple, white fracture and cleavage biaxial (-) nβ=1.680-1.682; 0.156 none bic polysynthetic