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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<br />

146<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 />

Actinolite can occur in both <strong>the</strong><br />

asbestiform <strong>and</strong> nonasbestiform<br />

mineral habits <strong>and</strong> is in <strong>the</strong> mineral<br />

series tremolite-ferroactinolite. 1<br />

The asbestiform variety is <strong>of</strong>ten<br />

referred to as actinolite asbestos.<br />

A monoclinic calcic amphibole<br />

intermediate between<br />

ferroactinolite <strong>and</strong> tremolite:<br />

Ca2(Fe,Mg) 5Si8O22(OH) 2;<br />

with Mg/(Mg+Fe2+ ) between<br />

0.5 <strong>and</strong> 0.9 (o<strong>the</strong>rwise if ≤<br />

0.5 it is ferroactinolite, <strong>and</strong><br />

if ≥ 0.9 it is tremolite).<br />

A bright-green or grayish-green monoclinic<br />

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

Ca2(Fe,Mg) 5(OH) 2[Si8O22]. It may contain<br />

manganese. It sometimes occurs in <strong>the</strong> form<br />

<strong>of</strong> asbestos, <strong>and</strong> also in fibrous, radiated, or<br />

columnar forms in metamorphic rocks (such<br />

as schists) <strong>and</strong> in altered igneous rocks.<br />

Actinolite A monoclinic mineral,<br />

2[Ca2(Fe,Mg) 5Si8O22(OH) 2];<br />

in <strong>the</strong> hornblende series Mg/<br />

(Mg+Fe2+ ) = 0.50 to 0.89 <strong>of</strong> <strong>the</strong><br />

amphibole group; forms a series<br />

with tremolite; green, bladed,<br />

acicular, fibrous (byssolite<br />

asbestos), or massive (nephrite<br />

jade); prismatic cleavage; in<br />

low-grade metamorphic rocks.<br />

Amosite is <strong>the</strong> commercial<br />

term derived from <strong>the</strong> acronym<br />

“<strong>Asbestos</strong> Mines <strong>of</strong> South Africa.”<br />

Amosite is in <strong>the</strong> mineral series<br />

cummingtonite-grunerite, 1 in<br />

which both asbestiform <strong>and</strong><br />

nonasbestiform habits <strong>of</strong> <strong>the</strong><br />

mineral can occur. This mineral<br />

type is commonly referred<br />

to as “brown asbestos.”<br />

A commercial term for an iron-rich,<br />

asbestiform variety <strong>of</strong> amphibole occurring<br />

in long fibers. It may consist <strong>of</strong> an<br />

orthorhombic amphibole (anthophyllite<br />

or gedrite) or <strong>of</strong> a monoclinic amphibole<br />

(cummingtonite or grunerite).<br />

Amosite 1. A monoclinic mineral in <strong>the</strong><br />

cummingtonite-grunerite series. 2<br />

2. A commercial asbestos<br />

composed <strong>of</strong> asbestiform gedrite,<br />

grunerite, or anthophyllite<br />

<strong>of</strong> <strong>the</strong> amphibole group;<br />

has typically long fibers.<br />

A macroscopically lamellar brown to green<br />

monoclinic serpentine mineral, which consists<br />

structurally <strong>of</strong> alternating wave forms<br />

in which <strong>the</strong> 1:1 T-O layer reverses sides<br />

<strong>and</strong> direction <strong>of</strong> curvature at each wave null<br />

point. In most specimens <strong>the</strong> repeat distance<br />

<strong>of</strong> <strong>the</strong> wave pattern measures between<br />

25.5 <strong>and</strong> 51.0 Å: (Mg, Fe2+ ) 3Si2O3(OH) 4.<br />

Antigorite A monoclinic mineral,<br />

(Mg,Fe) 3Si2O5(OH) 4; kaoliniteserpentine<br />

group; polymorphous<br />

with clinochrysotile, lizardite,<br />

orthochrysotile, parachrysotile;<br />

greasy variegated green;<br />

used as an ornamental stone.<br />

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

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

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