Talc
Talc is named after Arabic "talq" - pure (white), probably alluding to the colour of its powder.
Talc is the world's softest mineral with the Mohs hardness 1. It can be easily scratched by a fingernail. Talc is translucent to opaque with mother-of-pearl, greasy or dull lustre.
A coarse grayish-green high-talc rock soapstone or steatite is used for carvings and ornamental objects.
Talc is the world's softest mineral with the Mohs hardness 1. It can be easily scratched by a fingernail. Talc is translucent to opaque with mother-of-pearl, greasy or dull lustre.
A coarse grayish-green high-talc rock soapstone or steatite is used for carvings and ornamental objects.
| General Information | ||||||||||||||||||
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| Varieties/Types: | Steatite - A massive variety of Talc with a greasy feeling. | |||||||||||||||||
| Chemical Formula |
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| Physical Properties of Talc | ||||||||||||||||||
| Mohs Hardness | 1, Gemmological Tables (2004) | |||||||||||||||||
| Specific Gravity | 2.55 to 2.80, Gemstones of the world (2001) More from other references | |||||||||||||||||
| Cleavage Quality | Perfect, Gemmological Tables (2004) | |||||||||||||||||
| Optical Properties of Talc | ||||||||||||||||||
| Refractive Index | 1.539 to 1.596, Gemmological Tables (2004) | |||||||||||||||||
| Optical Character | Biaxial/-, Gemmological Tables (2004) | |||||||||||||||||
| Birefringence | 0.046 to 0.050, Gemmological Tables (2004) | |||||||||||||||||
| Colour | ||||||||||||||||||
| Colour (General) | Gray-green, pearl-white, blue-green, yellowish., Gemstones of the world (2001) More from other references | |||||||||||||||||
| Transparency | Translucent,Opaque, Gemstones of the world (2001) More from other references | |||||||||||||||||
| Lustre | Pearly,Greasy,Dull, Gemstones of the world (2001) | |||||||||||||||||
| Crystallography of Talc | ||||||||||||||||||
| Crystal System | Monoclinic, Gemstones of the world (2001) PseudohexagonalMore from other references | |||||||||||||||||
| Further Information | ||||||||||||||||||
| Mineral information: | Talc information at mindat.org | |||||||||||||||||