Talc is a secondary mineral that forms by the alteration of primary magnesium silicate minerals such as olivine. This alteration takes place in low-temperature metamorphic rocks and it is common to find talc in regions of mountain building. Sometimes, its massive form, soapstone, makes up nearly the entire rock mass.
| Mg3Si4O10(OH)2 |
|
| Phyllosilicate |
|
| Triclinic |
|
| -1 |
|
| 1 |
|
| 2.7-2.8 |
|
| {001} perfect |
|
| Uneven |
|
| Green, gray, white |
|
| White |
|
| Pearly, greasy |
|
| Translucent |
|
| Foliated, massive |
|
| Greasy feel |
|
| Notable Localities: |
Appalachian mountains, Vermont to Georgia; California; North Carolina; Texas |
| Uses: |
Paint, ceramics, rubber, insecticides, roofing, paper, talcum powder, carving material (soapstone) |
Specimens:
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