Properties
| Category | Phyllosilicate minerals |
|---|---|
| Formula | Mg3Si4O10(OH)2 |
| Crystal system | Monoclinic or triclinic |
| Color | Light to dark green, brown, white, grey, colorless |
| Crystal habit | Foliated to fibrous masses, rare as platey to pyramidal crystals |
| Cleavage | Perfect on {001} basal cleavage |
| Fracture | Flat surfaces (not cleavage), fracture in an uneven pattern |
| Tenacity | Sectile |
| Mohs scale hardness | 1 (defining mineral) |
| Luster | Waxy or pearly |
| Streak | White jot to pearl black |
| Diaphaneity | Translucent |
| Specific gravity | 2.58–2.83 |
From the Wikipedia article
Talc, or talcum, is a clay mineral composed of hydrated magnesium silicate, with the chemical formula Mg3Si4O10(OH)2. Talc in powdered form, often combined with corn starch, is used as baby powder. This mineral is used as a thickening agent and lubricant. It is an ingredient in ceramics, paints, and roofing material. It is a main ingredient in many cosmetics. It occurs as foliated to fibrous masses, and in an exceptionally rare crystal form. It has a perfect basal cleavage and an uneven flat fracture, and it is foliated with a two-dimensional platy form.
Source
Source record: crystal-compendium/talc/minerals.json. Fetched from English Wikipedia by the operator 2 October 2026.
https://en.wikipedia.org/wiki/Talc — revision id 1376613763. Text and properties from Wikipedia, licensed CC BY-SA 4.0.