The fibers that constitute asbestos are long, flexible strands of six minerals (amosite, chrysotile, crocidolite, and the varieties tremolite, actinolite and anthophyllite) that can be combined or used separately. These minerals occur naturally in the environment and are resistant to heat, chemical reactions and have low electrical conductivity. Given the strength and flexibility of the fibers, asbestos has been used in various industrial and commercial building products.
Asbestos can be separated into two major groups: serpentine and amphibole. Under the two major groups are three common asbestos types:
Chrysotile, also known as white asbestos, has a curly shape and makes up 90% of asbestos in products. It belongs to the serpentine group and is a magnesium silicate.
Amosite fibers are brown or gray in color and resemble a straight lock of hair when viewed under a microscope. They are a part of the amphibole group and contain iron and magnesium.
Crocidolite is also a member of the amphibole group and has a blue hue. They are straight and spiked in shape and are a sodium iron magnesium silicate.
Amphibole fibers are the most hazardous to health, but all types of asbestos can lead to health problems. Because Chrysotile fibers were used most often, they are the type most commonly known to be the source of asbestos-related disease.