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Trigonal crystal system
584 minerals
| Mineral | Chemical formula | Mohs hardness | Density |
|---|---|---|---|
| Brucite | Mg(OH)₂ | 2.5 | 2.46 g/cm³ |
| Bubnovaite | K₂Na₈Ca(SO₄)₆ | — | — |
| Buryatite | Ca₃(Si,Fe,Al)(SO₄)[B(OH)₄]O(OH)₅·12H₂O | — | — |
| Bystrite | (Na,K)₇Ca(Al₆Si₆O₂₄)(S₅)Cl | — | — |
| Byzantievite | Ba₅(Ca,REE,Y)₂₂(Ti,Nb)₁₈(SiO₄)₄[(PO₄),(SiO₄)]₄(BO₃)₉O₂₂[(OH),F]₄₃·₁.₅H₂O | — | — |
| Bütschliite | — | — | — |
| Calcite | CaCO₃ | 3.0 | 2.72 g/cm³ |
| Camaronesite | Fe³⁺₂(PO₃OH)₂(SO₄)(H₂O)₄·1-2H₂O | — | — |
| Carbobystrite | Na₈(Al₆Si₆O₂₄)(CO₃)·4H₂O | — | — |
| Carbocalumite | — | — | — |
| Carbokentbrooksite | Na₁₁-₁₂(Na,Ce)₃Ca₆Mn₃Zr₃Nb[(Si₃O₉)₂(Si₉O₂₇)₂SiO](OH)₃(CO₃) * H₂O | — | — |
| Caresite | Fe²⁺₄Al₂(OH)₁₂[CO₃] * 3H₂O | — | — |
| Carlfrancisite | Mn²⁺₃(Mn²⁺,Mg,Fe³⁺,Al)₄₂(As³⁺O₃)₂(As⁵⁺O₄)₄[(Si,As⁵⁺)O₄]₆[(As⁵⁺,Si)O₄]₂(OH)₄₂ | — | — |
| Carlgieseckeite-(Nd) | NaNdCa₃(PO₄)₃F | — | — |
| Carlinite | Tl₂S | 1.0 | — |
| Carlosruizite | K₃Na₂Na₃Mg₅(IO₃)₆(SeO₄)₆·6H₂O | — | — |
| Caswellsilverite | NaCrS₂ | — | 3.24 g/cm³ |
| Celleriite | — | 7.0 | — |
| Centennialite | CaCu₃Cl₂(OH)₆·nH₂O (n~0.7) | — | — |
| Chabazite-Ca | Ca₂[Al₄Si₈O₂₄]·13H₂O | — | — |
| Chabazite-K | (K₂NaCa₀.₅)[Al₄Si₈O₂₄]·11H₂O | — | — |
| Chabazite-Mg | (Mg₀.₇K₀.₅Ca₀.₅Na₀.₁)[Al₃Si₉O₂₄]·10H₂O | — | — |
| Chabazite-Na | (Na₃K)[Al₄Si₈O₂₄]·11H₂O | — | — |
| Chabazite-Sr | (Sr,Ca)₂[Al₄Si₈O₂₄]·11H₂O | — | — |
| Chalcophanite | ZnMn⁴⁺₃O₇·3H₂O | 2.5 | — |
| Chalcophyllite | Cu₁₈Al₂(AsO₄)₄(SO₄)₃(OH)₂₄·36H₂O | 2.0 | — |
| Changbaiite | PbNb₂O₆ | 5.5 | — |
| Changesite-(Ce) | (Ca₈Ce)◻Fe(PO₄)₇ | — | — |
| Changesite-(Y) | (Ca₈Y)◻Fe²⁺(PO₄)₇ | — | — |
| Charlesite | Ca₆Al₂(SO₄)₂B(OH)₄(OH,O)₁₂·26H₂O | — | — |
| Chinleite-(Ce) | NaCe(SO₄)₂(H₂O) | — | — |
| Chinleite-(Nd) | — | — | — |
| Chinleite-(Y) | NaY(SO₄)₂·H₂O | — | — |
| Chladniite | Na₂CaMg₇(PO₄)₆ | — | — |
| Chloraluminite | AlCl₃·6H₂O | — | — |
| Chlorartinite | Mg₂CO₃Cl(OH)·2.5H₂O | — | — |
| Chlormanganokalite | K₄[MnCl₆] | — | — |
| Chorążewiczite | Pb₂Fe³⁺(Te⁶⁺O₆)(HCO₃) | — | — |
| Chromium-dravite | Na(Mg₃)Cr³⁺₆(Si₆O₁₈)(BO₃)₃(OH)₃(OH) | — | — |
| Chromo-alumino-povondraite | NaCr₃(Al₄Mg₂)(Si₆O₁₈)(BO₃)₃(OH)₃O | 7.5 | — |
| Chubarovite | KZn₂(BO₃)Cl₂ | — | — |
| Cinnabar | HgS | 2.3 | 8.10 g/cm³ |
| Claraite | (Cu,Zn)₁₅(CO₃)₄(AsO₄)₂(SO₄)(OH)₁₄*₇H₂O | 2.0 | — |
| Clarkeite | (Na,Ca,Pb)(UO₂)O(OH) * ₀-₁H₂O | — | — |
| Cleusonite | (Pb,Sr)(U₄+,U₆+)(Fe²⁺,Zn)₂(Ti,Fe²⁺,Fe³⁺)₁₈(O,OH)₃₈ | — | — |
| Clogauite | PbBi₄Te₄S₃ | — | — |
| Cloudite | BaFe³⁺₃(PO₄)(SO₄)(OH)₆ | — | — |
| Coalingite | Mg₁₀Fe³⁺₂(CO₃)(OH)₂₄·2H₂O | — | — |
| Colquiriite | CaLiAlF₆ | — | 2.86 g/cm³ |
| Combeite | Na₂Ca₂Si₃O₉ | — | — |
| Comblainite | Ni₄Co³⁺₂(CO₃)(OH)₁₂·3H₂O | — | — |
| Congolite | (Fe²⁺,Mg)₃(B₇O₁₃)Cl | — | — |
| Coquimbite | — | 2.0 | — |
| Corkite | PbFe³⁺₃(SO₄)(PO₄)(OH)₆ | — | — |
| Corundum | Al₂O₃ | 9.0 | — |
| Cossaite | (Mg₀.₅,☐)Al₆(SO₄)₆(HSO₄)F₆·36H₂O | — | — |
| Crandallite | CaAl₃(PO₄)(PO₃OH)(OH)₆ | 5.0 | — |
| Cualstibite | Cu₂Al(OH)₆[Sb₅+(OH)₆] | — | — |
| Cuatrocapaite-(K) | K₃(NaMg☐)(As₂O₃)₆Cl₆(H₂O)₁₆ | — | — |
| Cuatrocapaite-(NH4) | (NH₄)₃(NaMg☐)(As₂O₃)₆Cl₆·(H₂O)₁₆ | — | — |
| Cupropearceite | [Cu₆As₂S₇][Ag₉CuS₄] | — | — |
| Cupropolybasite | [Cu₆Sb₂S₇][Ag₉CuS₄] | — | — |
| Daqingshanite-(Ce) | (Sr,Ca,Ba)₃(Ce,La)(CO₃)₃₋ₓ(PO₄)(OH,F)₂ₓ | — | — |
| Dargaite | BaCa₁₂(SiO₄)₄(SO₄)₂O₃ | — | — |
| Darrellhenryite | Na(Al₂Li)Al₆(Si₆O₁₈)(BO₃)₃(OH)₃O | 7.0 | — |
| Davinciite | Na₁₂K₃Ca₆Fe²⁺₃Zr₃(Si₂₆O₇₃OH)Cl₂ | — | — |
| Delafossite | Cu¹⁺Fe³⁺O₂ | — | — |
| Desautelsite | Mg₆Mn³⁺₂(CO₃)(OH)₁₆·4H₂O | — | — |
| Dessauite-(Y) | Sr(Y,U,Mn)(Ti,Fe,Cr,V)₁₈(O,OH)₃₈ | — | — |
| Deynekoite | — | — | — |
| Digenite | Cu₁.₈S | — | — |
| Dioptase | CuSiO₃·H₂O | 5.0 | — |
| Dobrovolskyite | Na₄Ca(SO₄)₃ | — | — |
| Dolomite | CaMg(CO₃)₂ | — | 2.87 g/cm³ |
| Dorallcharite | TlFe³⁺₃(SO₄)₂(OH)₆ | — | — |
| Dravite | NaMg₃Al₆(Si₆O₁₈)(BO₃)₃(OH)₃OH | 7.0 | — |
| Droninoite | Ni₆Fe³⁺₂Cl₂(OH)₁₆·4H₂O | — | — |
| Dugganite | Pb₃Zn₃(TeO₆)(AsO₄)₂ | 3.0 | 6.58 g/cm³ |
| Dukeite | Bi³⁺₂₄Cr⁶⁺₈O₅₇(OH)₆·3H₂O | — | — |
| Dulanggouite | Bi₆Te₃ | — | — |