Silicate – zeolite, most commonly found in veins and cavities in igneous rocks, prehnite occurs in very low-grade metamorphic rocks, and as a product of the decomposition of plagioclase feldspar. It sometimes occurs as an epimorph, which is a crystal growth over another mineral.
Prehnite removes toxins from the system, helps the metabolism and bloodstream to function more efficiently, balances the meridians in the body and calms high blood pressure.
Prehnite is named after Major Prehn, who discovered it at the end of the eighteenth century in South Africa. It was used as a stone of prophecy and shamanism by indigenous sangomas (medicine men and women). It is known as the prophecy stone.