Asullite

Asullite is a rare aluminosilicate mineral that crystallizes in the monoclinic system. Its composition is dominated by aluminum, silicon, and oxygen, with trace amounts of sodium and fluorine. The mineral forms translucent to transparent crystals with a pale blue to colorless appearance and a vitreous luster. Mohs hardness is reported around 6, and it exhibits weak cleavage along a single direction.

Discovery and naming: Asullite was described from the Asulla region, which gave the mineral its name. The type material was collected during a regional survey in the late 20th century by researchers at the Institute of Mineralogy. It has been accepted as a valid mineral species by the International Mineralogical Association (IMA).

Occurrence and habitat: Asullite forms in hydrothermally altered, high-grade metamorphic rocks, often in association with other aluminosilicates and quartz. The type locality is Asulla Peak, a lithologically diverse mountainous area providing fluid-rich conditions conducive to its growth.

Structure and classification: The crystal structure comprises interconnected aluminum and silicon tetrahedra forming layered sheets, yielding a framework silicate with moderate interlayer bonding. Because full single-crystal data are limited, the exact space group remains tentative, though it is generally described as a layered aluminosilicate related to other silicate minerals.

Significance and uses: Research interest centers on its formation conditions and its role as a geologic indicator of metamorphic and hydrothermal processes. There are no known commercial applications, but asullite contributes to mineralogical databases and classification efforts.