Anosite “Brown Asbestos”
Amosite, is a trade name associated with matieral from amphiboles belonging to the Cummingtonite – Grunerite solid solution series, commonly from Africa, mainly the Asbestos Mines of South Africa. It is found most frequently as a fire retardant in thermal insulation products and ceiling tiles.
Crocidolite “Blue Asbestos”
Crocidolite is an amphibole found primarily in southern Africa, but also in Australia. It is the fibrous form of the amphibole riebeckite.Chrysotile commonly occurs as soft friable fibers.
Asbestiform amphibole may also occur as soft friable fibers but some varieties such as amosite are commonly straighter.
All forms of asbestos are fibrillar in that they are composed of fibers with widths less than 1 micrometer that occur in bundles and have very long lengths. Asbestos with particularly fine fibers is also referred to as “amianthus”.
Amphiboles such as tremolite have a crystal structure containing strongly bonded ribbonlike silicate anion polymers that extend the length of the crystal. Serpentine (chrysotile) has a sheetlike silicate anion which is curved and which rolls up like a carpet to form the fiber.
Other Forms of Asbestos
Other regulated asbestos minerals, such as tremolite asbestos, actinolite asbestos, and anthophyllite asbestos, are less commonly used industrially but can still be found in a variety of construction materials and insulation materials and have been reported in the past to occur in a few consumer products.
Other natural and not currently regulated asbestiform minerals, such as richterite and winchite may be found as a contaminant in products such as the vermiculite containing zonolite insulation manufactured by some of today’s major manufacturers. These minerals are thought to be no less harmful than tremolite, amosite, or crocidolite, but since they are not regulated, they are referred to as “asbestiform” rather than asbestos although may still be related to diseases and hazardous.
