Formula: Cu2(AsO4)(OH) · 3H2O

Species: Arsenates

Colour: Bright emerald-green, leek-green; bright bluish green in transmitted light.

Lustre: Vitreous

Hardness: 3½ – 4

Specific Gravity: 3.44

Crystal System: Orthorhombic

Name: Named in 1823 by August Breithaupt from the Greek ευχροια for “beautiful color.”

Type Locality: Svätodušná deposit, Ľubietová, Banská Bystrica District, Banská Bystrica Region, Slovakia

A rare secondary copper arsenate. Metastable by comparison to related copper arsenates; may be pseudomorphed by olivenite.