Erythrite (Co₃(AsO₄)₂·8H₂O) is a hydrous cobalt arsenate — the secondary “cobalt bloom” alteration product of primary cobalt arsenide ores (skutterudite, cobaltite). Its diagnostic crimson-pink to magenta color is unmistakable. Bou Azzer (Morocco) and Schneeberg (Germany) supply iconic specimens. Toxic — handle with gloves due to soluble arsenic content.
Key Facts
- Mohs hardness 1.5–2.5.
- Monoclinic; acicular, prismatic, and radiating fibrous habit.
- Diagnostic crimson to magenta-pink color.
- Forms by oxidation of skutterudite, cobaltite, and other Co-As primary minerals.
- Toxic — soluble arsenate; wash hands after handling.
Notable Localities
Bou Azzer (Morocco) is the world standard. Schneeberg (Saxony, Germany) is the type-area. Cobalt (Ontario, Canada) yields historic specimens.
Found at these Localities
- Bou Azzer District (布·阿扎尔钴矿区)
- Erzgebirge / Krušné Hory (埃尔茨山脉/克鲁什内山(德捷边境矿带))
- Cobalt, Ontario (安大略科博尔特银矿)
- Imiter Mine (伊米泰尔银矿)
