Erythrite
Species
Uncommon · Co₃(AsO₄)₂·8H₂O
Cobalt bloom: a crimson to peach pink hydrated cobalt arsenate that crusts weathered cobalt arsenide ores. It has never been an economically important mineral in itself, but it shows the prospector where cobalt ore and native silver lie. First described in 1832 from the Daniel mine at Schneeberg in Saxony; Bou Azzer in Morocco gives large crystals.
Identity
- Formula
- Co₃(AsO₄)₂·8H₂O
- Chemical class
- Phosphate
- Also known as
- Cobalt bloom, Red cobalt, Cobalt ochre
- Ore of
- Cobalt
Crystallography
- Crystal system
- Monoclinic
- Habits
- Prismatic, Fibrous, Drusy, Earthy
- Fracture
- Uneven
Physical properties
- Mohs hardness
- 2
- Density
- 3.06 g/cm³
- Luster
- Adamantine, Pearly
- Colors
- deep red, pink, pale pink
- Streak
- pale red to pink
- Transparency
- Transparent, Translucent
Geology
- Origins
- Sedimentary
- Associated minerals
- Cobaltite, Skutterudite, Malachite
- Found in
- Oxidized zone (gossan)
- Geography
- Germany (Schneeberg, Saxony; Wittichen), Czech Republic (Jáchymov), Morocco (Bou Azzer), Canada (Cobalt, Ontario), Chile (La Cobaltera), Australia (Mount Cobalt, Queensland)
Classification
- Rarity
- Uncommon
- Gem quality
- No
Sources
- M. Pasero and others, IMA Commission on New Minerals, Nomenclature and Classification, The New IMA List of Minerals, updated September 2026. International Mineralogical Association (CNMNC), 2026.
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Erythrite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
- Erythrite. Wikipedia.
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