Pillerit

Pillerit is a rare mineral belonging to the zeolite group, characterized by its unique crystal structure and composition. It was first discovered in the Pillersee, a lake in the Austrian Alps, in 1973, and is named after this location. The mineral is typically colorless or white, but can also appear in shades of yellow, green, or brown due to impurities. Pillerit crystallizes in the monoclinic system and is often found in small, prismatic crystals or in compact masses.

The chemical formula of pillerit is Na2Ca2(Si8Al4O24)•8H2O. It is composed of sodium, calcium, silicon, aluminum, oxygen, and water. The mineral is known for its low hardness, with a Mohs hardness of 3.5 to 4, making it relatively soft. Pillerit is also known for its low density, with a specific gravity of approximately 2.2 to 2.3.

Pillerit is typically found in sedimentary rocks, particularly in areas with a history of volcanic activity. It is often associated with other zeolite minerals such as chabazite and analcime. The mineral has limited commercial value but is of interest to mineral collectors and geologists due to its rarity and unique properties. Pillerit's formation is closely related to the alteration of volcanic glass and other silicate minerals in the presence of alkaline fluids.