Asisite: Properties and Occurrence

Asisite (Formula- Pb₇SiO₈Cl₂) is a yellow tetragonal mineral. It is a very rare lead oxyhalide found only at the Kombat mine.

Asisite was named after the Asis farm located at the Kombat mine, Namibia. It is found at Kombat Mine, Kombat, Grootfontein District, Otjozondjupa Region, Namibia. It was named for a farm, Asis, which covers the mine where it was found. It was discovered in 1988. It is distributed mainly in Namibia in the Kombat mine, 49 km south of Tsumeb.

General Information

Category: Halide
Formula: Pb₇SiO₈Cl₂
Crystal system: Tetragonal
Space group: Tetragonal.

Properties

Asisite can be identified in the field by its green-yellow and yellow color variations. Its transparent form has {001} perfect cleavage. This mineral has an adamantine luster with the yellow-white streak. The hardness of asisite is 3.5- approximate to a copper penny.

Color: yellow to yellow-green, red
Mohs scale hardness: 3.5
Cleavage: {001} Perfect
Diaphaneity: Transparent
Habit: Platy – Sheet forms (e.g. micas).
Hardness: 3.5 – Copper Penny
Luster: Adamantine
Streak: yellow white

Occurrence

Asisite occurs in manganese silicate lenses nearby a sulfide ore body. It is often associated with minerals such hematophanite, chlorite, barite, hematite, molybdophyllite, jacobsite, and copper,

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