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Subject: [stone] Getting Started
Date: Wed, 16 Feb 2000 07:58:58 -0500
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List-Name: stone
Regarding making talc safe for general use, e.g.. baby
powder. The primary health hazard seems to be when talc
is inhaled into the lungs over an extended period of
time. When applied externally to the body, you do not
inhale appreciable amounts of it. The powder and dust
produced when working with chisels and rifflers is very
fine and should not be inhaled.
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This topic seems to have a general interest so I have
included for your information some definitions below:
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Soapstone is a soft metamorphic rock composed mostly of
the mineral talc. Also called steatite. (From its smooth
soapy feel)
Talcum powder or talc is a mineral Mg3Si4O10(OH)2
consisting of a basic magnesium tetrasilicate. It is a
fine-grained white, greenish, or gray mineral, having a
soft soapy feel and used in talcum and face powder, as a
paper coating, and as a filler for paint and plastics.
Talc, soft, greasy, granular or fibrous mineral composed
of an acid metasilicate of magnesium, H2Mg3(SiO3)4. It
crystallizes in the monoclinic and orthorhombic systems.
Talc has a hardness of 1 to 1.5 and a specific gravity
of 2.7 to 2.8. It exhibits perfect basal cleavage. The
mineral ranges in color from apple-green or gray to
silver-white and shines with a pearly to greasy luster.
Talc is exceedingly common and occurs in large beds of
crystalline schists together with serpentine, dolomite,
and chlorite. The principal deposits exist in the United
States. Talc is used in soaps, lubricants, tailor's
chalk, pigments, and talcum powder.
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