Euchroite is a hydrated copper arsenate hydroxide mineral with formula: Cu<sub>2</sub>AsO<sub>4</sub>OH÷3H<sub>2</sub>O. It is a vitreous green to emerald green mineral crystallizing in the orthorhombic system. It has a Mohs hardness of 3.5âÂÂ4.0 and a specific gravity of 3.39âÂÂ3.45. It was first described in 1823 in ýubietová, Slovakia.