THE GEMSTONE LIBRARY
Australian Prehnite
Australian Prehnite brings translucent green and yellow color to polished cabochons. These pieces were offered in our December 2025 collection as Australian Bio Prehnite.
What is prehnite?
Prehnite is a calcium-aluminium silicate mineral with the formula Ca₂Al₂Si₃O₁₀(OH)₂. Its orthorhombic structure, glassy luster and typically green-to-yellow color give it a distinctive appearance. Its Mohs hardness is about 6–6.5; cleavage and brittleness also matter when choosing a jewelry setting.
Australian occurrences
Prehnite forms in cavities and veins in volcanic rocks and in some rocks affected by low-grade metamorphism. Documented Australian occurrences include the Warrumbungle region and Prospect Hill in New South Wales. Gem material is also reported from Wave Hill in the Northern Territory.
Australia is the supplied provenance for the photographed cabochons. Their precise locality and accompanying minerals have not been established here. “Bio Prehnite” is retained as the collection name; it is not a separate mineral species or a claim about biological origin.
Sources
Mineralogical Society of America — Prehnite · Australian producer — Wave Hill prehnite locality