The meaning of Prehnites and additional information.

Prehnite(n.) A pale green mineral occurring in crystalline aggregates having a botryoidal or mammillary structure, and rarely in distinct crystals. It is a hydrous silicate of alumina and lime.

Prehnitic(a.) Pertaining to, or designating, a tetrabasic acid of benzene obtained as a white crystalline substance; -- probably so called from the resemblance of the wartlike crystals to the mammillae on the surface of prehnite.