- Home
- Crystal systems
- Trigonal
Trigonal crystal system
584 minerals
| Mineral | Chemical formula | Mohs hardness | Density |
|---|---|---|---|
| Oskarssonite | AlF₃ | — | 3.26 g/cm³ |
| Otavite | CdCO₃ | — | 4.96 g/cm³ |
| Oxy-chromium-dravite | NaCr₃(Cr₄Mg₂)(Si₆O₁₈)(BO₃)₃(OH)₃O | 7.5 | — |
| Oxy-dravite | Na(Al₂Mg)(Al₅Mg)(Si₆O₁₈)(BO₃)₃(OH)₃O | 7.0 | — |
| Oxy-foitite | ☐(Fe²⁺Al₂)Al₆(Si₆O₁₈)(BO₃)₃(OH)₃O | 7.0 | — |
| Oxy-schorl | Na(Fe²⁺₂Al)Al₆(Si₆O₁₈)(BO₃)₃(OH)₃O | 7.0 | — |
| Oxy-vanadium-dravite | Na(V)₃(V₄Mg₂)Si₆O₁₈(BO₃)₃(OH)₃O | 7.5 | — |
| Palmierite | K₂Pb(SO₄)₂ | — | 4.13 g/cm³ |
| Paqueite | Ca₃TiSi₂(Al,Ti,Si)₃O₁₄ | — | — |
| Paracoquimbite | Fe₂(SO₄)₃ * 9H₂O | — | — |
| Paragonite | NaAl₂(Si₃Al)O₁₀(OH)₂ | — | — |
| Parahibbingite | — | — | — |
| Paralstonite | BaCa(CO₃)₂ | — | — |
| Paratacamite-(Mg) | Cu₃(Mg,Cu)Cl₂(OH)₆ | — | — |
| Paratacamite-(Ni) | Cu₃(Ni,Cu)Cl₂(OH)₆ | — | — |
| Paseroite | Pb(Mn²⁺,☐)(Fe³⁺,☐)₂(V⁵⁺,Ti⁴⁺,☐)₁₈O₃₈ | — | — |
| Pauloabibite | NaNbO₃ | — | — |
| Pearceite | Cu(Ag,Cu)₆Ag₉As₂S₁₁ | — | — |
| Perhamite | Ca₃Al₇.₇Si₃P₄O₂₃.₅(OH)₁₄.₁ · 8H₂O | — | — |
| Perryite | (Ni,Fe)₅(Si,P)₂ | — | — |
| Pertoldite | GeO₂ | — | 6.21 g/cm³ |
| Pezzottaite-(Cs) | Cs(Be₂Li)Al₂(Si₆O₁₈) | 8.0 | — |
| Phenakite | Be₂SiO₄ | — | 2.96 g/cm³ |
| Pilsenite | Bi₄Te₃ | — | — |
| Plumbogummite | PbAl₃(PO₄)(PO₃OH)(OH)₆ | — | — |
| Plumbojarosite | PbFe³⁺₆(SO₄)₄(OH)₁₂ | — | — |
| Plumbonacrite | Pb₅(CO₃)₃O(OH)₂ | — | — |
| Poellmannite | — | — | — |
| Portlandite | Ca(OH)₂ | 2.0 | 2.30 g/cm³ |
| Povondraite | NaFe³⁺₃(Mg₂Fe³⁺₄)(Si₆O₁₈)(BO₃)₃(OH)₃O | 7.0 | — |
| Princivalleite | — | 7.0 | — |
| Proshchenkoite-(Y) | Ca(Y,REE,Ca,Na,Mn)₁₅Fe²⁺(P,Si)Si₆B₃O₃₄F₁₄ | 5.0 | — |
| Proustite | Ag₃AsS₃ | — | 5.39 g/cm³ |
| Pyracmonite | (NH₄)₃Fe(SO₄)₃ | — | — |
| Pyrargyrite | Ag₃SbS₃ | 2.8 | 5.80 g/cm³ |
| Pyrochroite | Mn²⁺(OH)₂ | — | — |
| Pyrophanite | Mn²⁺TiO₃ | — | — |
| Qaqarssukite-(Ce) | BaCe(CO₃)₂F | — | — |
| Qeltite | Ca₃TiSi₂(Fe³⁺₂Si)O₁₄ | — | — |
| Qiumingite | Pb₃(Zn₂Fe³⁺)Sb⁵⁺P₂O₁₄ | — | — |
| Quartz | SiO₂ | 7.0 | 2.65 g/cm³ |
| Quetzalcoatlite | Cu²⁺₃Zn₆Te⁶⁺₂O₁₂(OH)₆·(Ag,Pb,☐)Cl | 3.0 | — |
| Ranciéite | (Ca,Mn²⁺)₀.₂(Mn⁴⁺,Mn³⁺)O₂·0.6H₂O | — | — |
| Raslakite | Na₁₅Ca₃Fe²⁺₃(Na,Zr)₃Zr₃(Si,Nb)[(Si₃O₉)₂(Si₉O₂₇)₂SiO](OH,H₂O)₃(Cl,OH) | — | — |
| Rastsvetaevite | Na₂₇K₈Ca₁₂Fe₃Zr₆Si₅₂O₁₄₄(O,OH,H₂O)₆Cl₂ | — | — |
| Reevesite | Ni₆Fe³⁺₂(OH)₁₆(CO₃) * 4H₂O | 2.0 | — |
| Rhabdophane-(Ce) | CePO₄·H₂O | — | — |
| Rhodochrosite | MnCO₃ | — | 3.74 g/cm³ |
| Rhodplumsite | Rh₃Pb₂S₂ | — | 9.79 g/cm³ |
| Rodolicoite | Fe³⁺PO₄ | — | — |
| Rosiaite | PbSb₂O₆ | — | 6.89 g/cm³ |
| Rossmanite | ☐(LiAl₂)Al₆(Si₆O₁₈)(BO₃)₃(OH)₃(OH) | 7.0 | — |
| Rotemite | Ca₄Cr₂(OH)₁₂Cl₂·4H₂O | — | — |
| Röntgenite-(Ce) | Ca₂Ce₃(CO₃)₅F₃ | — | — |
| Sabieite | (NH₄)Fe³⁺(SO₄)₂ | — | — |
| Saltonseaite | K₃NaMnCl₆ | — | 2.25 g/cm³ |
| Saranovskite | — | — | — |
| Satterlyite | (Fe²⁺,Mg,Fe)₁₂(PO₄)₅(PO₃OH)(OH,O)₆ | — | — |
| Scacchite | MnCl₂ | — | 2.92 g/cm³ |
| Schairerite | Na₂₁(SO₄)₇ClF₆ | — | — |
| Schlossmacherite | (H₃O)Al₃(SO₄)₂(OH)₆ | — | — |
| Schorl | Na(Fe²⁺₃)Al₆(Si₆O₁₈)(BO₃)₃(OH)₃(OH) | 7.0 | — |
| Schuetteite | Hg²⁺₃(SO₄)O₂ | — | — |
| Schulenbergite | (Cu,Zn)₇(SO₄)₂(OH)₁₀·3H₂O | 2.0 | — |
| Schöllhornite | — | — | — |
| Scordariite | — | — | — |
| Scorticoite | — | — | — |
| Selenium | Se | — | — |
| Selenopolybasite | Cu(Ag,Cu)₆Ag₉Sb₂(S,Se)₉Se₂ | — | — |
| Sergevanite | — | — | — |
| Shandite | Ni₃Pb₂S₂ | 4.0 | 8.73 g/cm³ |
| Sheldrickite | — | — | — |
| Shigaite | Mn₆Al₃(OH)₁₈[Na(H₂O)₆](SO₄)₂ * 6H₂O | — | — |
| Shijiangshanite | Pb₃CaAl(Si₅O₁₄)(OH)₃(H₂O)₃ | — | — |
| Siderite | FeCO₃ | 4.0 | 3.96 g/cm³ |
| Simpsonite | Al₄Ta₃O₁₃(OH) | 7.5 | — |
| Siwaqaite | Ca₆Al₂(CrO₄)₃(OH)₁₂·26H₂O | — | — |
| Skippenite | Bi₂TeSe₂ | — | — |
| Slavíkite | — | — | — |
| Slottaite | SrFe³⁺₃(PO₄)(SO₄)(OH)₆ | — | — |