Tremolite

Trémolite-Barège

Tremolite-121232

Tremolite is a member of the amphibole group of silicate minerals. It forms by metamorphism of sediments rich in dolomite and quartz. Tremolite is a common constituent of some metamorphic rocks, such as marble, where its presence can give the rock a pleasing white color. However, its presence is also a marker for potential asbestos contamination in some forms, particularly when fibrous, which can pose significant health risks.

Properties and Composition

Tremolite is a calcium magnesium silicate mineral with the chemical formula Ca_2(Mg,Fe)_5Si_8O_22(OH)_2. The iron-rich variety is known as ferro-tremolite. Tremolite forms a series with actinolite and ferro-actinolite, with varying magnesium and iron content being the primary differentiator between these minerals. Pure tremolite is colorless, but the presence of iron and other trace elements can give it a range of colors, from white to dark green or even black.

Formation and Occurrence

Tremolite is primarily formed through the metamorphism of ultramafic rocks and carbonate rocks under high-pressure and low-temperature conditions. It is commonly found in metamorphic rocks such as schists and marbles. Tremolite can also occur as a secondary mineral in igneous rocks and is often associated with talc, serpentine, and other magnesium-rich minerals.

Health Risks

The fibrous form of tremolite is classified as asbestos. Inhalation of asbestos fibers can lead to serious diseases, such as asbestosis, mesothelioma, and lung cancer. The health risks associated with asbestos have led to its regulation in many countries. Non-fibrous tremolite, however, does not pose the same health risks as the fibrous variety.

Uses

Historically, tremolite asbestos was used in a variety of applications, including insulation, roofing materials, and fireproofing. However, due to the health risks associated with asbestos, the use of tremolite in these applications has been greatly reduced or eliminated in many jurisdictions.

See Also

• Amphibole
• Asbestos
• Metamorphic rocks
• Mineralogy