chrysocolla (chrys-o-col'-la). (a) A blue, blue-green, or emerald-green amorphous mineral: Cu₂(OH)₄[Si₂O₃(OH)₂]. It occurs as incrustations and thin seams in the zone of weathering of copper ores. Its chemical composition was formerly given as: CuSiO₃•2H₂O. (b) An old name given to a mineral or minerals (such as chrysocolla, borax, and malachite) used for soldering gold (Hey, 1962, p.384).