Variscite

Variscite is a rare hydrated aluminum phosphate mineral with the chemical formula AlPO4·2H2O. It forms as green to green-blue nodules in sedimentary rocks, especially phosphate-bearing limestones and sandstones, typically through diagenetic precipitation from phosphate-bearing fluids. The name derives from Variscia, the historic name for a region in the Vogtland area of Saxony, Germany, where the mineral was first described.

Variscite is usually opaque to translucent and has a waxy to resinous luster. It has a Mohs hardness of about 4 and a specific gravity around 1.9–2.3. Color ranges from bright to pale green, with blue-green varieties occasionally observed.

Distribution and occurrence: In addition to Germany, variscite occurs at several localities worldwide, with notable deposits in the western United States, including Utah and Nevada, as well as in Idaho and Australia. It commonly forms as nodules or botryoidal masses within phosphate-rich sedimentary sequences and may be found in association with turquoise and other phosphates.

Uses and significance: Variscite is collected by mineral enthusiasts and used as a gemstone and ornamental material. Its green color and resemblance to turquoise lead to frequent comparisons with turquoise, though variscite is generally softer and more brittle, which influences its care and suitability for jewelry. High-quality material is carved into cabochons and beads, while more common material serves as specimens for collectors.