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

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Table 2. Definitions <strong>of</strong> specific minerals (Continued)<br />

Glossary <strong>of</strong> Geology, 5th ed.<br />

[American Geological Institute 2005] Leake et al. [1997] NIOSH [1990a]<br />

Dictionary <strong>of</strong> Mining,<br />

<strong>Mineral</strong>, <strong>and</strong> Related Terms<br />

[U.S. Bureau <strong>of</strong> Mines 1996]<br />

[Note: Footnotes identify <strong>the</strong> Primary<br />

Source Citation for <strong>the</strong> definition]<br />

Term<br />

NIOSH CIB 62 • <strong>Asbestos</strong><br />

A colorless or white monoclinic zeolite<br />

mineral. Usually designated as phillipsite<br />

– (Ca, K, or Na) depending on which<br />

is <strong>the</strong> dominant exchangeable cation,<br />

(Ca,K,Na) •<br />

2(Si,Al) 8O16 6H2O.<br />

Phillipsite A monoclinic mineral, (K,Na,Ca) 1-<br />

2(Si,Al) 8O16.6H2O; zeolite group;<br />

commonly occurs in complex<br />

twinned crystals; in basalt<br />

amydules, in pelagic red clays, in<br />

palagonite tuffs, in alkaline saline<br />

lakes from silicic vitric volcanic<br />

ash, in alkaline soils, <strong>and</strong> around<br />

hot springs in Roman baths.<br />

A monoclinic sodic-calcic<br />

amphibole: Na(CaNa)<br />

Mg5Si8O22(OH) 2; may also<br />

contain divalent iron but<br />

with Mg/(Mg+Fe2+ ) ≥ 0.5<br />

(o<strong>the</strong>rwise it is ferrorichterite)<br />

Richterite A brown, yellow, or rose-red monoclinic<br />

member <strong>of</strong> <strong>the</strong> amphibole group:<br />

Na2CaMg5Si8O22(OH) 2. Cf: soda tremolite<br />

A monoclinic sodic amphibole:<br />

Na2(Fe2+ 3Fe3+ 2)Si8O22(OH) 2;<br />

may also contain aluminum<br />

in place <strong>of</strong> trivalent iron but<br />

with VIAl < Fe3+ o<strong>the</strong>rwise it is<br />

ferroglaucophane, <strong>and</strong> may also<br />

contain sodium <strong>and</strong> potassium<br />

in <strong>the</strong> A position but with<br />

(Na+K) A < 0.50 o<strong>the</strong>rwise it<br />

is arfvedsonite, <strong>and</strong> may also<br />

contain magnesium in place<br />

<strong>of</strong> divalent iron but with Mg/<br />

(Mg+Fe2+ ) < 0.5 o<strong>the</strong>rwise<br />

it is magnesioriebeckite<br />

A dark blue or black monoclinic mineral <strong>of</strong> <strong>the</strong><br />

amphibole group: Na2Fe2+ 3Fe3+ 2Si8O22(OH) 2. It<br />

occurs as a primary constituent in some acid or<br />

sodium-rich igneous rocks. See also: crocidolite<br />

Riebeckite A monoclinic mineral, Na2Ca (Mg,Fe2+ ) 5Si8O22(OH) 2 [sic];<br />

amphibole group with Mg/<br />

(Mg+Fe2+ ) = 0 to 0.49 <strong>and</strong> Fe3+ /<br />

(Fe3+ +Al) = 0.7 to 1.0; forms a<br />

series with magnesioriebeckite;<br />

fibrous; in soda-rich rhyolites,<br />

granites, <strong>and</strong> pegmatites;<br />

crocidolite variety is blue<br />

asbestos; tiger eye is crocidolite<br />

replaced by quartz.<br />

See footnotes at end <strong>of</strong> table. (Continued)<br />

151

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