The Collaborative International Dictionary
Euchroite
Euchroite \Eu"chro*ite\, n. [See Euchroic.] (Min.) A mineral occurring in transparent emerald green crystals. It is hydrous arseniate of copper.
Wiktionary
euchroite
n. (context mineral English) A green hydrated copper arsenate hydroxide mineral.
Wikipedia
Euchroite
' Euchroite' is a hydrated copper arsenate hydroxide mineral with formula: CuAsOOH·3HO. It is a vitreous green to emerald green mineral crystallizing in the orthorhombic system. It has a Mohs hardness of 3.5 - 4.0 and a specific gravity of 3.39 - 3.45. It was first described in 1823 in Ľubietová, Slovakia.