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Trigonal crystal system
584 minerals
| Mineral | Chemical formula | Mohs hardness | Density |
|---|---|---|---|
| Smithsonite | ZnCO₃ | 5.0 | 4.46 g/cm³ |
| Somersetite | Pb₈O₂(OH)₂(CO₃)₅ | — | — |
| Spangolite | Cu₆AlSO₄(OH)₁₂Cl·3H₂O | — | — |
| Spherocobaltite | CoCO₃ | 4.0 | 4.29 g/cm³ |
| Spionkopite | Cu₃₉S₂₈ | — | 5.13 g/cm³ |
| Spiridonovite | (Cu₁-xAgx)₂Te | — | — |
| Stavelotite-(La) | La₃Mn²⁺₃Cu²⁺(Mn³⁺,Fe³⁺,Mn⁴⁺)₂₆(Si₂O₇)₆O₃₀ | — | — |
| Steenstrupine-(Ce) | Na₁₄Ce₆Mn²⁺₂Fe³⁺₂Zr(PO₄)₇Si₁₂O₃₆(OH)₂·3H₂O | — | — |
| Steklite | KAl(SO₄)₂ | — | — |
| Stepanovite | NaMgFe³⁺(C₂O₄)₃·9H₂O | 2.0 | — |
| Stibarsen | SbAs | — | — |
| Stibiosegnitite | Pb(Fe³⁺₂.₅Sb⁵⁺₀.₅)(AsO₄)₂(OH)₆ | — | — |
| Stichtite | Mg₆Cr₂CO₃(OH)₁₆·4H₂O | — | — |
| Stillwaterite | Pd₈As₃ | — | — |
| Stillwellite-(Ce) | CeBSiO₅ | — | 4.74 g/cm³ |
| Stillwellite-(La) | LaBSiO₅ | — | — |
| Stistaite | SnSb | 3.0 | — |
| Stracherite | BaCa₆(SiO₄)₂[(PO₄)(CO₃)]₂F | — | — |
| Sturmanite | Ca₆Fe³⁺₂(SO₄)₂.₅[B(OH)₄](OH)₁₂·25H₂O | 2.5 | — |
| Sudovikovite | PtSe₂ | — | 8.42 g/cm³ |
| Sulfhydrylbystrite | Na₅K₂Ca[Al₆Si₆O₂₄](S₅)²⁻(SH)⁻ | — | — |
| Susannite | Pb₄(SO₄)(CO₃)₂(OH)₂ | — | — |
| Svanbergite | SrAl₃(SO₄)(PO₄)(OH)₆ | — | — |
| Szilagyiite | NaCa₃(UO₂)(CO₃)₃(SeO₃)F(H₂O)₆ | — | — |
| Tachyhydrite | CaMg₂Cl₆·12H₂O | 2.0 | — |
| Taipingite-(CeCa) | (Ce₇Ca₂)Mg(SiO₄)₃[SiO₃(OH)]₄F₃ | — | — |
| Takedaite | — | — | — |
| Takovite | Ni₆Al₂(OH)₁₆[CO₃]·4H₂O | — | — |
| Tancaite-(Ce) | FeCe(MoO₄)₃·3H₂O | — | — |
| Taranakite | K₃Al₅(PO₃OH)₆(PO₄)₂·18H₂O | — | — |
| Taseqite | Na₁₂Sr₃Ca₆Fe₃Zr₃Nb[(Si₃O₉)₂(Si₉O₂₇)₂SiO]Cl₂(O,OH,H₂O)₃ | — | — |
| Tegengrenite | (Mn³⁺₀.₅Sb⁵⁺₀.₅)Mg₂O₄ | — | — |
| Tellurantimony | Sb₂Te₃ | — | 6.12 g/cm³ |
| Tellurium | Te | — | — |
| Tellurobismuthite | Bi₂Te₃ | — | 7.32 g/cm³ |
| Telluronevskite | Bi₃TeSe₂ | — | — |
| Telyushenkoite | (Cs,Na,K)Na₆[Be₂Al₃Si₁₅O₃₉]F₂ | — | — |
| Tetradymite | Bi₂Te₂S | — | 7.09 g/cm³ |
| Theophrastite | Ni(OH)₂ | — | — |
| Tiberiobardiite | {Cu₉Al[SiO₃(OH)]₂(OH)₁₂(H₂O)₆}(SO₄)₁.₅·10H₂O | — | — |
| Tilkerodeite | — | 3.0 | 9.67 g/cm³ |
| Tincalconite | Na₂B₄O₅(OH)₄·3H₂O | — | — |
| Tisinalite | Na₃H₃(Mn,Ca,Fe)TiSi₆(O,OH)₁₈ * 2H₂O | — | — |
| Tistarite | Ti₂O₃ | — | — |
| Tombstoneite | — | — | — |
| Tondiite | Cu₃MgCl₂(OH)₆ | — | — |
| Torryweiserite | — | — | — |
| Townendite | Na₈ZrSi₆O₁₈ | — | — |
| Trembathite | (Mg,Fe)₃(B₇O₁₃)Cl | — | — |
| Trébeurdenite | Fe²⁺₂Fe³⁺₄O₂(OH)₁₀(CO₃)·3H₂O | — | — |
| Tsilaisite | NaMn²⁺₃Al₆(Si₆O₁₈)(BO₃)₃(OH)₃(OH) | 7.0 | — |
| Tsumoite | BiTe | — | — |
| Tuite | Ca₃(PO₄)₂ | — | 2.78 g/cm³ |
| Tuliokite | Na₆BaTh(CO₃)₆·6H₂O | — | — |
| Tusionite | Mn²⁺Sn₄+[BO₃]₂ | — | — |
| Tveitite-(Y) | (Y,Na)₆Ca₆Ca₆F₄₂ | — | — |
| Tzeferisite | CaZn₈(SO₄)₂(OH)₁₂Cl₂(H₂O)₉ | — | — |
| Ungemachite | K₃Na₈Fe³⁺(SO₄)₆(NO₃)₂·6H₂O | 2.5 | — |
| Uvite | — | 7.5 | — |
| Uytenbogaardtite | Ag₃AuS₂ | 2.0 | — |
| Vadlazarenkovite | Pd₈Bi₁.₅Te₁.₂₅As₀.₂₅ | — | — |
| Valleriite | 2[(Fe,Cu)S]·1.53[(Mg,Al)(OH)₂] | — | — |
| Vanackerite | Pb₄Cd(AsO₄)₃Cl | — | 7.28 g/cm³ |
| Vanadio-oxy-chromium-dravite | NaV₃(Cr₄Mg₂)(Si₆O₁₈)(BO₃)₃(OH)₃O | 7.5 | — |
| Vanadio-oxy-dravite | NaV₃(Al₄Mg₂)(Si₆O₁₈)(BO₃)₃(OH)₃O | 7.5 | — |
| Voronkovite | Na₁₅(Na,Ca,Ce)₃(Mn,Ca)₃Fe₃Zr₃Si₂₆O₇₂(OH,O)₄Cl·H₂O | — | — |
| Walthierite | Ba₀.₅Al₃(SO₄)₂(OH)₆ | — | — |
| Wangdaodeite | FeTiO₃ | — | — |
| Wassonite | TiS | — | 4.46 g/cm³ |
| Waylandite | BiAl₃(PO₄)₂(OH)₆ | — | — |
| Welinite | Mn²⁺₆(W₆+,Mg)₂(SiO₄)₂(O,OH)₆ | — | — |
| Wermlandite | Mg₇Al₂(OH)₁₈[Ca(H₂O)₆][SO₄]₂ * ₆H₂O | — | — |
| Whitlockite | Ca₉Mg(PO₄)₆(PO₃OH) | 5.0 | — |
| Wickenburgite | CaPb₃Al₂Si₁₀O₂₄(OH)₆ | — | — |
| Wiklundite | Pb₂[₄](Mn²⁺,Zn)₃(Fe³⁺,Mn²⁺)₂(Mn²⁺,Mg)₁₉(As³⁺O₃)₂[(Si,As₅+)O₄]₆(OH)₁₈Cl₆ | — | — |
| Wildcatite | — | — | — |
| Willemite | Zn₂SiO₄ | 5.5 | 4.25 g/cm³ |
| Woodallite | Mg₆Cr₂(OH)₁₆Cl₂·4H₂O | — | — |
| Woodhouseite | CaAl₃(SO₄)(PO₄)(OH)₆ | 4.5 | — |
| Wopmayite | Ca₆Na₃☐Mn(PO₄)₃(PO₃OH)₄ | — | — |