Erythrite crystallises in the monoclinic system and forms prismatic crystals. The colour is crimson to pink and occurs as a secondary coating known as cobalt bloom on cobalt arsenide minerals.

Erythrite was first described in 1832 for an occurrence in Grube Daniel, Schneeberg, Saxony, and takes its name from the Greek (erythros), meaning red. Historically, erythrite itself has not been an economically important mineral, but the prospector may use it as a guide to associated cobalt and native silver.