Petalite

Petalite is a lithium aluminum silicate mineral with the chemical formula LiAlSi4O10. It forms in lithium-rich igneous environments, especially granitic pegmatites, and occurs in rocks that host other lithium-bearing minerals. In many deposits it is found alongside quartz, alkali feldspar, spodumene, lepidolite, beryl, and amblygonite. Petalite is an important, though not exclusive, source of lithium.

Physical properties of petalite include typically colorless to white crystals, with pale yellow, pink, or greenish tints in some specimens. It has a vitreous to pearly luster and a white streak. Crystals are often tabular or prismatic and may occur in sizable aggregates within pegmatites. The mineral tends to be relatively well cleaved for a silicate and can be distinguished from similarly colored minerals by its chemical composition and lithium content.

Economically, petalite serves as a source of lithium, which is recovered in processing to produce lithium compounds used in batteries, glass, ceramics, and other chemical applications. While not the sole lithium ore, petalite contributes to supply in lithium-rich districts and is important in some pegmatite deposits.

Taxonomically, petalite is classified as a lithium aluminum silicate and is typically identified through mineralogical analysis, including chemical assays and, when available, crystallography. Its distinguishing features include lithium content, silicate framework, and association with other lithium-bearing minerals. As with many minerals, field identification can be challenging without laboratory confirmation.