from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A fibrous, lavender-blue or greenish mineral, a sodium iron silicate that is used as a commercial form of asbestos.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A fibrous, blue-green mineral that is an asbestos-like form of riebeckite.
from the GNU version of the Collaborative International Dictionary of English
- n. A mineral occuring in silky fibers of a lavender blue color. It is related to hornblende and is essentially a silicate of iron and soda; -- called also blue asbestus. A silicified form, in which the fibers penetrating quartz are changed to oxide of iron, is the yellow brown tiger-eye of the jewelers.
from The Century Dictionary and Cyclopedia
- n. A mineral consisting principally of silicate of iron and sodium, occurring in asbestos-like fibers of a delicate blue color, and also massive, in Griqualand, South Africa, and in the Vosges mountains of France and Germany. Also called blue asbestos.
It is recommended to generally forbid the mining and further processing of the particularly hazardous Asbestos types, namely crocidolite and amosite.
A cohort study of miners employed at the mine reported that while no deaths occurred within the first 10 years after crocidolite exposure, 85 deaths attributable to mesothelioma had occurred by 1985.
South Africa mined crocidolite, amosite and chrysotile asbestos extensively from the late 1800s until 2001.
Because certain kinds - among them chrysotile (white), crocidolite (blue), and amosite (brown) - are durable, resist heat, and possess fire-retardant properties, they were once widely used for insulation and fireproofing.
The geology of asbestos centers on the the three most common types: chrysotile, amosite, and crocidolite.
Such applications used mainly chrysotile or amosite, although crocidolite was commonly used in Europe, this practice was discontinued in the 1970s because of health concerns.
The tensile strengths of amosite and crocidolite are comparable to that of chrysotile.
Only three varieties of amphibole fibers will be discussed because: crocidolite and amosite were the only amphiboles with significant industrial uses in recent years; tremolite, although having essentially no industrial application, may be found as a contaminant in other fibers or in other industrial minerals (e.g., chrysotile and talc).
The trend observed of increasing tensile strength of amphiboles from tremolite, to amosite, to crocidolite is directly related to the iron content of these fibers.
For example, at 350° C, crocidolite has lost 50% of its initial tensile strength.