amblygonite

Amblygonite is a phosphate mineral with the chemical formula LiAl(PO4)F. It is a member of the amblygonite group, which also includes montebrasite. The two are considered end-members of a solid solution series, with amblygonite being the fluorine-rich end and montebrasite being the hydroxyl-rich end. The exact chemical formula can be represented as LiAl(PO4)(F,OH), where the ratio of fluorine to hydroxyl varies.

Amblygonite is typically found in pegmatites and hydrothermal veins. It often occurs in association with other lithium-bearing minerals such as spodumene, lepidolite, and tourmaline, as well as feldspar and quartz. The mineral is known for its vitreous to greasy luster and can range in color from colorless to white, gray, yellow, or pink. Crystals are usually prismatic or tabular.

This mineral is significant as a primary source of lithium, a metal crucial for batteries, ceramics, and glass manufacturing. Its hardness is between 5 and 6 on the Mohs scale, making it relatively brittle. Amblygonite was first described in 1840 from a locality in Saxony, Germany. Its name is derived from the Greek words "amblys" meaning blunt and "gonia" meaning angle, referring to its indistinct cleavage angles.