Prehnite - Natural minerals and crystals

The mineral Prehnite is a calcium aluminum silicate. It usually appears as pale green to yellow crystals, although its color can vary depending on its exact chemical composition. Prehnite is the first mineral to be named and described in South Africa, and it is notable for being one of the first minerals to crystallize during low-grade metamorphism. It has a hardness of 6 to 6.5 on the Mohs scale, which makes it relatively resistant to erosion and wear. It is generally translucent, with a glassy to pearly sheen. Prehnite is often used as an ornamental stone because of its beautiful color and shine.