The Probert Encyclopaedia of Rocks & Minerals

CHRYSOPRASE

Chrysoprase is a green variety of chalcedony, coloured by nickel. When heated or exposed to sunlight the mineral often becomes paler, the colour being restored after exposure to moisture. It is a brittle mineral and is inclined to crack in cutting or setting. It is often extremely beautiful, so that it is much esteemed in jewelry. It is translucent, or sometimes semi-transparent, and of a hardness a little inferior to that of flint.
Research Chrysoprase