What Is Asbestos?
|
Asbestos is not a single material, but rather a group of six different minerals. There are five characteristics that all minerals share: |
|
|
|
Minerals are NATURALLY OCCURRING |
|
|
Minerals are SOLID |
|
|
Minerals are INORGANIC (Minerals were never alive.) |
|
|
Minerals have specific CHEMICAL COMPOSITIONS |
|
|
Minerals have specific ARRANGEMENTS OF THEIR ATOMS |
|
Because each mineral is composed of a unique set of elements and/or these atoms are arranged in specific patterns, each mineral will have a unique set of physical properties. Although each asbestos mineral has its own unique properties, all six asbestos minerals share the following additional physical properties: |
|
|
|
Asbestos is FIBROUS (Length > 3x Width) |
|
|
Asbestos is a THERMAL INSULATOR |
|
|
Asbestos is RESISTANT TO HEAT |
|
|
Asbestos is CHEMICALLY RESISTANT |
|
|
Asbestos has HIGH TENSILE STRENGTH (Withstands being stretched) |
|
Of the six asbestos minerals, only three have been used commonly as a constituent of building materials, with one mineral (chrysotile) comprising approximately 95% of all of the asbestos used. Amosite and crocidolite make up most of the remaining 5%. These three minerals will be the focus of your exploration of asbestos and its potential hazard. |
||
| CHRYSOTILE | AMOSITE | CROCIDOLITE |
| "White Asbestos" | "Brown Asbestos" | "Blue Asbestos" |
| Serpentine Group | Amphibole Group | Amphibole Group |
| Mg3Si2O7· 2H2O | (Fe,Mg)6Si8O23· H2O | Na2Fe4Si8O23· H2O |
|
|
|
|
© 2001 Wayne G. Powell
