Are these shaggy—looking minerals, collectively called asbestos, hazardous to your health? Some are—under certain circumstances. Asbestos is a commercial term for several distinct fibrous minerals. Because each mineral has a unique atomic structure, chemistry, and set of properties, evaluating the health risks associated with asbestos is a complex problem. Despite the controversy about their safety, some asbestos minerals are still used because of their strength and resistance to heat.

Crocidolite
If they are inhaled, needlelike fibers of crocidolite can penetrate deeply into the lungs, making it the most dangerous asbestos mineral. It was once important in shipbuilding but is rarely used today. Known as blue asbestos, crocidolite is a variety of riebeckite.

Chrysotile
Commonly used in brake linings and roofing, chrysotile, or white asbestos, is a member of the serpentine family.