Diaspore

Diaspore is a hydroxide mineral primarily composed of aluminium oxide-hydroxide, with the chemical formula AlO(OH). It is an important ore of aluminium and is often found in bauxite deposits. Diaspore is known for its orthorhombic crystal system and typically forms elongated, flattened crystals.

Properties

Diaspore has a Mohs hardness of 6.5 to 7 and a specific gravity of approximately 3.3 to 3.5. It exhibits perfect cleavage in one direction, which can make it challenging to cut and polish for use in gemstones. The mineral is usually colorless or white, but it can also appear in shades of yellow, green, or brown due to the presence of impurities.

Occurrence

Diaspore is commonly found in bauxite deposits, which are the primary source of aluminium. It can also occur in metamorphic rocks such as schist and marble, and in sedimentary rocks like limestone. Significant deposits of diaspore are found in countries such as Turkey, Greece, Russia, and the United States.

Uses

The primary use of diaspore is as an ore of aluminium. It is also used as a refractory material due to its high melting point and resistance to thermal shock. In recent years, gem-quality diaspore, often marketed under the name Zultanite, has gained popularity in the jewelry industry.

Related Minerals

Diaspore is closely related to other aluminium hydroxide minerals such as boehmite and gibbsite. These minerals often occur together in bauxite deposits and are collectively referred to as the aluminium hydroxide group.

See Also

• Bauxite
• Aluminium
• Orthorhombic crystal system
• Mohs hardness scale
• Refractory material