Cobaltoblödite
| Cobaltoblödite | |
|---|---|
| General | |
| Category | Sulfate mineral |
|
Formula (repeating unit) |
Na2Co(SO4)2•4H2O |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H-M symbol) |
| Space group | P21/a |
| Unit cell | a = 11.15, b = 8.27, c = 5.54 [Å], β=100.52° (approximated); Z = 2 |
| Identification | |
| Color | Colorless (grains), reddish-pink (aggregates) |
| Crystal habit | anhedral grains, in aggregates, forming crusts |
| Cleavage | None |
| Fracture | Uneven |
| Mohs scale hardness | ca. 2.5 |
| Luster | Vitreous |
| Streak | White |
| Diaphaneity | Transparent |
| Density | 2.29 (measured), 2.35 (calculated) (approximated) |
| Optical properties | Biaxal (-) |
| Refractive index | nα=1.50, nβ=1.50, nγ=1.51 (approximated) |
| Common impurities | Mg, Co, Ni |
| References | |
Cobaltoblödite is a very rare cobalt mineral with the formula Na2Mn(SO4)2•4H2O. Cobaltoblödite was found in the Blue Lizard mine, San Juan County, Utah, USA, which is known for secondary uranium minerals Cobaltoblödite occurs intimately intergrown with manganese-, cobalt- and nickel-enriched blödite and a yet another new mineral - manganoblödite. Cobaltoblödite, as suggested by its name is a cobalt-analogue of blödite. It is also analogous to changoite, manganoblödite and nickelblödite - other members of the blödite group.
Manganoblödite is impure, containing admixtures of magnesium, manganese and nickel.
Besite blödite and cobaltoblödite, other minerals associated with manganoblödite include chalcanthite, gypsum, johannite, sideronatrite, a feldspar group-mineral and quartz.
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