Facts
- Symbol
- Co
- Atomic number
- 27
- Atomic mass
- 58.9 u
- Minerals
- 70
- Period
- 4
- Group
- 9
- Block
- d
- Melting point
- 2,719 °C
- Boiling point
- 5,612 °C
- Discovered
- 1735
Sources: Wikidata (CC0), IMA list of minerals via Wikidata · Wikidata Q740
Minerals containing this element · 70
| Mineral | Chemical formula | Crystal system | Mohs hardness | Density |
|---|---|---|---|---|
| Alloclasite | CoAsS | Monoclinic | — | 6.26 g/cm³ |
| Anorthoroselite | Ca₂Co(AsO₄)₂·2H₂O | Triclinic | — | — |
| Aplowite | Co(SO₄)·4H₂O | Monoclinic | — | — |
| Asbolane | Mn⁴⁺(O,OH)₂·(Co,Ni,Mg,Ca)ₓ(OH)₂ₓ·nH₂O | Hexagonal | — | — |
| Bieberite | CoSO₄·7H₂O | Monoclinic | 2.0 | — |
| Bornhardtite | Co²⁺Co³⁺₂Se₄ | Cubic | 4.0 | — |
| Bouazzerite | Bi₆(Mg,Co)₁₁Fe₁₄(AsO₄)₁₈O₁₂(OH)₄·86H₂O | Monoclinic | — | — |
| Burgessite | Co₂(H₂O)₄[AsO₃(OH)]₂(H₂O) | Monoclinic | — | — |
| Carrollite | CuCo₂S₄ | Cubic | — | 4.92 g/cm³ |
| Cattierite | CoS₂ | Cubic | — | 4.85 g/cm³ |
| Clinosafflorite | CoAs₂ | Monoclinic | — | 7.55 g/cm³ |
| Cobaltarthurite | (Co,Mg)Fe³⁺₂(AsO₄)₂(OH)₂ * 4H₂O | — | — | — |
| Cobaltaustinite | CaCo(AsO₄)(OH) | Orthorhombic | — | — |
| Cobaltite | CoAsS | Orthorhombic | 5.5 | 6.26 g/cm³ |
| Cobaltkieserite | Co(SO₄)(H₂O) | Monoclinic | — | — |
| Cobaltkoritnigite | Co(AsO₃OH)·H₂O | Triclinic | — | — |
| Cobaltlotharmeyerite | CaCo₂(AsO₄)₂·2H₂O | — | 4.5 | 4.13 g/cm³ |
| Cobaltoblödite | Na₂Co(SO₄)₂·4H₂O | Monoclinic | — | — |
| Cobaltomenite | CoSe⁴⁺O₃·2H₂O | — | — | — |
| Cobaltpentlandite | Co₉S₈ | Cubic | — | 5.70 g/cm³ |
| Cobalttsumcorite | PbCo₂(AsO₄)₂·2H₂O | — | — | 5.31 g/cm³ |
| Cobaltzippeite | Co(UO₂)₂(SO₄)O₂ * 3.₅H₂O | Monoclinic | — | — |
| Cochromite | (Co,Ni,Fe)(Cr,Al)₂O₄ | Cubic | — | — |
| Comblainite | Ni₄Co³⁺₂(CO₃)(OH)₁₂·3H₂O | Trigonal | — | — |
| Costibite | CoSbS | — | — | 7.02 g/cm³ |
| Erythrite | Co₃(AsO₄)₂·8H₂O | Monoclinic | — | — |
| Ferroskutterudite | (Fe,Co)As₃ | Cubic | — | — |
| Fletcherite | Cu(Ni,Co)₂S₄ | Cubic | — | — |
| Freboldite | CoSe | Hexagonal | — | — |
| Glaucodot | (Co₀.₅Fe₀.₅)AsS | Orthorhombic | 5.0 | 6.06 g/cm³ |
| Gritsenkoite | CoMg₂(AsO₄)₂(H₂O)₈ | Monoclinic | — | — |
| Guite | Co²⁺Co³⁺₂O₄ | Cubic | — | — |
| Heterogenite | Co³⁺O(OH) | Hexagonal | — | — |
| Hloušekite | (Ni,Co)Cu₄(AsO₄)₂(AsO₃OH)₂·9H₂O | Triclinic | — | — |
| Jaipurite | CoS | Hexagonal | — | — |
| Julienite | Na₂[Co(SCN)₄]·8H₂O | Monoclinic | — | — |
| Karpenkoite | Co₃(V₂O₇)(OH)₂·2H₂O | Trigonal | — | — |
| Kieftite | CoSb₃ | Cubic | — | 7.59 g/cm³ |
| Kolwezite | CuCo(CO₃)(OH)₂ | Triclinic | — | — |
| Langisite | (Co,Ni)As | Hexagonal | — | — |
| Leverettite | Cu₃CoCl₂(OH)₆ | Trigonal | — | — |
| Linnaeite | Co₃S₄ | Cubic | — | 4.77 g/cm³ |
| Mattagamite | CoTe₂ | Orthorhombic | — | 7.79 g/cm³ |
| Metakirchheimerite | Co(UO₂)₂(AsO₄)₂·8H₂O | — | — | — |
| Modderite | (Co,Fe)As | Orthorhombic | 4.0 | — |
| Moorhouseite | Co(SO₄)(H₂O)₆ | Monoclinic | — | — |
| Nickelskutterudite | (Ni,Co,Fe)As₃ | Cubic | — | — |
| Oenite | CoSbAs | Orthorhombic | — | — |
| Oursinite | Co(UO₂)₂(SiO₃OH)₂·6H₂O | — | — | — |
| Pakhomovskyite | Co₃(PO₄)₂·8H₂O | — | — | — |
| Paracostibite | CoSbS | — | — | 7.02 g/cm³ |
| Perchiazziite | Co₂(CO₃)(OH)₂ | Monoclinic | — | — |
| Petewilliamsite | (Ni,Co)₃₀(As₂O₇)₁₅ | Monoclinic | — | — |
| Pradetite | CoCu₄(AsO₄)₂(AsO₃OH)₂·9H₂O | — | — | — |
| Rappoldite | PbCo₂(AsO₄)₂·2H₂O | Triclinic | 4.5 | 5.28 g/cm³ |
| Roselite | Ca₂Co(AsO₄)₂·2H₂O | Monoclinic | 3.5 | — |
| Safflorite | CoAs₂ | Orthorhombic | — | 7.55 g/cm³ |
| Schneebergite | BiCo₂(AsO₄)₂(OH)·H₂O | — | 4.5 | — |
| Siegenite | CoNi₂S₄ | Cubic | — | — |
| Skutterudite | CoAs₃ | Cubic | — | 6.84 g/cm³ |
Minerals named after it · 15
| Mineral | Chemical formula | Crystal system | Mohs hardness | Density |
|---|---|---|---|---|
| Cobaltarthurite | (Co,Mg)Fe³⁺₂(AsO₄)₂(OH)₂ * 4H₂O | — | — | — |
| Cobaltaustinite | CaCo(AsO₄)(OH) | Orthorhombic | — | — |
| Cobaltite | CoAsS | Orthorhombic | 5.5 | 6.26 g/cm³ |
| Cobaltkieserite | Co(SO₄)(H₂O) | Monoclinic | — | — |
| Cobaltkoritnigite | Co(AsO₃OH)·H₂O | Triclinic | — | — |
| Cobaltlotharmeyerite | CaCo₂(AsO₄)₂·2H₂O | — | 4.5 | 4.13 g/cm³ |
| Cobaltneustädtelite | — | — | 4.5 | — |
| Cobaltoblödite | Na₂Co(SO₄)₂·4H₂O | Monoclinic | — | — |
| Cobaltomenite | CoSe⁴⁺O₃·2H₂O | — | — | — |
| Cobaltpentlandite | Co₉S₈ | Cubic | — | 5.70 g/cm³ |
| Cobalttsumcorite | PbCo₂(AsO₄)₂·2H₂O | — | — | 5.31 g/cm³ |
| Cobaltzippeite | Co(UO₂)₂(SO₄)O₂ * 3.₅H₂O | Monoclinic | — | — |
| Cochromite | (Co,Ni,Fe)(Cr,Al)₂O₄ | Cubic | — | — |
| Costibite | CoSbS | — | — | 7.02 g/cm³ |
| Spherocobaltite | CoCO₃ | Trigonal | 4.0 | 4.29 g/cm³ |