This is an old revision of this page, as edited by Heron (talk | contribs) at 13:14, 8 January 2003 (mineralogical details; deleted "formerly", as it's still used in some countries). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
Revision as of 13:14, 8 January 2003 by Heron (talk | contribs) (mineralogical details; deleted "formerly", as it's still used in some countries)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)Asbestos is a type of fibrous metamorphic mineral. The fibres are typically mixed with cement or woven into mats. It is used in buildings for its flame-retardant and insulating properties, but is now known to be carcinogenic and is banned in many countries.
Types of asbestos
- Chrysotile, or white asbestos, is obtained from Canadian serpentine rocks. It is less friable, and therefore less likely to be inhaled, than the other types and is still used industrially.
- Amosite, or brown asbestos, is an amphibolic variety from Africa.
- Crocidolite, or blue asbestos, is an amphibolic variety from Africa and Australia.
Notes: Serpentine rocks are those with with curled fibres. Amphibolic rocks have straight, needle-like fibres.
The amphibolic types, in their fibrous form, are friable and therefore the most carcinogenic, although they also exist in safer non-fibrous forms.
Other asbestos minerals, such as tremolite, actinolite and anthophyllite are not used industrially but occur in traces. Riebeckite is another variety.
In the United States, asbestos was one of the first hazardous air pollutants regulated under Section 112 of the Clean Air Act of 1970.
Asbestos sometimes gets into phone lines and causes problems with DSL and modem connections.
See also: List of minerals, Eternit