Asbestos Fibers and Other Elongate Mineral Particles: State of the ...

Table 1. Definitions of general mineralogical terms (Continued)
136
Glossary of Geology, 5th ed.
[American Geological
Institute 2005] Leake et al. [1997] NIOSH [1990a]
Dictionary of Mining,
Mineral, and Related
Terms [U.S. Bureau
of Mines 1996]
[Note: Footnotes identify the Primary
Source Citation for the definition]
Term
Asbestos is a generic term for a
number of silicate minerals with
a fibrous crystalline structure.
The quality of commercially used
asbestos depends on the mineralogy
of the asbestiform variety, the
degree of fiber development, the
ratio of fibers to acicular crystals
or other impurities, and the length
and flexibility of the fibers. The
asbestiform varieties of these
minerals can be found in both the
amphibole and serpentine mineral
groups. The asbestiform varieties
occur in veins or small veinlets
within rock containing or composed
of the common (nonasbestiform)
variety of the same mineral.
1. A commercial term applied to a group
of silicate minerals that readily separate
into thin, strong fibers that are flexible,
heat resistant, and chemically inert, and
are therefore suitable for uses (as in yarn,
cloth, paper, paint, brake linings, tiles,
insulation, cement, fillers, and filters)
where incombustible, nonconducting, or
chemically resistant material is required.
2. A mineral of the asbestos group [sic],
principally chrysotile (best adapted
for spinning) and certain fibrous
varieties of amphibole (esp. amosite,
anthophyllite, and crocidolite).
3. A term strictly applied to the
fibrous variety of actinolite. Certain
varieties are deleterious to health.
Asbestos1 1. A commercial term
applied to silicate minerals
that separate readily into
thin, strong fibers that
are flexible, heat resistant,
and chemically inert, thus
making them suitable for
uses (as in yarn, cloth, paper,
paint, brake linings, tiles,
insulation, cement, fillers, and
filters) where incombustible,
nonconducting, or chemically
resistant material is required.
Since the early 1970’s,
there have been serious
environmental concerns
about the potential health
hazards of asbestos products,
which has resulted in strong
environmental regulations.
The major asbestiform varieties
of minerals used commercially
are chrysotile, tremolite-actinolite
asbestos, cummingtonite-grunerite
asbestos, anthophyllite asbestos, and
crocidolite. Asbestos is marketed by
its mineral name (e.g., anthophyllite
asbestos), its variety name (e.g.,
chrysotile or crocidolite), or its
trade name (e.g., Amosite).
2. Any asbestiform
mineral of the serpentine
group (chrysotile, best
adapted for spinning and
the principal variety in
commerce) or amphibole
group (esp. actinolite,
anthophyllite, gedrite,
cummingtonite, grunerite,
riebeckite, and tremolite).
3. A term strictly applied
to asbestiform actinolite.
NIOSH CIB 62 • Asbestos
See footnotes at end of table. (Continued)