batoliite

Batoliite is a rare and distinctive mineral belonging to the sorosilicate group, characterized by its unique crystal structure and composition. It was first identified in 1969 at the Batola mine in the Kolar Gold Fields of Karnataka, India, from which it derives its name. The mineral is typically found in pegmatites, which are coarse-grained igneous rocks formed from slowly crystallizing magma.

Batoliite has a chemical formula of Ca₄Fe²⁺₃(Fe³⁺,Al)₂(Si₄O₁₂)₂(Si₂O₇)₂(OH)₄·2H₂O, indicating its complex composition, which includes calcium, iron (both ferrous and ferric), aluminum, silicon, oxygen, and water. Its crystals are usually tabular or prismatic, often exhibiting a greenish to brownish hue, though they can also appear colorless or pale yellow. The mineral is known for its vitreous to resinous luster and a hardness of approximately 5.5 on the Mohs scale, making it relatively durable.

Batoliite is most commonly associated with other rare minerals such as fluorite, quartz, and various iron-bearing silicates. Due to its scarcity, batoliite is primarily of interest to mineralogists and collectors rather than having industrial applications. Specimens are often sought after for their aesthetic qualities and scientific significance in studying pegmatite formations.

The mineral’s occurrence is limited to a few localities worldwide, with notable findings in India, Brazil, and the United States. Its study contributes to the understanding of complex silicate structures and the geological processes that lead to their formation.