Roselite
| Roselite | |
|---|---|
Roselite druse in a vug from Morocco (size:12.8 x 8.5 x 5.9 cm)
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| General | |
| Category | Arsenate minerals |
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Formula (repeating unit) |
Ca2(Co2+, Mg)[AsO4]2·H2O |
| Strunz classification | 8.CG.10 |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H-M symbol) |
| Space group | P21/c |
| Unit cell | a = 5.801 Å, b = 12.898 Å c = 5.617 Å; β = 107.42°; Z = 2 |
| Identification | |
| Color | Dark rose red, pink |
| Crystal habit | Elongated crystals and spherical aggregates and druses |
| Twinning | Common as composition plane, contact twins and fourlings |
| Cleavage | {010} Perfect |
| Mohs scale hardness | 3.5 |
| Luster | Vitreous |
| Streak | Light red |
| Specific gravity | 3.69 |
| Optical properties | Biaxial (-) |
| Refractive index | nα = 1.725 nβ = 1.728 nγ = 1.735 |
| Pleochroism | Visible |
| 2V angle | Calculated: 68° |
| References | |
Roselite is a rare arsenate mineral with chemical formula: Ca2(Co,Mg)[AsO4]2·H2O. It was first described in 1825 for an occurrence in the Rappold mines of Schneeberg, Saxony, Germany and named by Armand Lévy after German mineralogist Gustav Rose. It occurs in cobalt bearing hydrothermal environments and was associated with veins of quartz and chalcedony in the type locality. It has also been reported from Italy, Morocco, Chile, British Columbia and several locations in Germany.
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