Erythrite - Co₃(AsO₄)₂·8H₂O

Habit: Crimson to peach red, pale rose or pink. Rarely well crystallized, typically flattened; as aggregates, fibrous, drusy, powdery or massive. Subadamantine luster; transparent to translucent. Pinkish red streak.

Environment: A secondary mineral associated with some cobalt/ nickel/arsenic-bearing mineral deposits.

Etymology: From the Greek word for red, its characteristic color.