silicates
Talc
Mg3Si4O10(OH)2
- Also known as
- soapstonesteatiteFrench chalk
- Crystal system
- monoclinic
- Hardness
- 1 on the Mohs scale
- Lustre
- pearly
- Colour
- White, grey, pale green
- Where it forms
- By alteration of magnesium-rich rocks, usually serpentinite and dolomite, under hydrothermal conditions.
- Chiefly from
- Trimouns, FranceLiaoning, ChinaVermont, United StatesIndia
Why it is that colour
Essentially colourless; impurities give the tints. Its defining characteristic is not colour but softness — it is the softest mineral on the Mohs scale and can be scratched with a fingernail.
Safety
Pure talc is inert and among the most benign minerals there is. The problem is what it forms alongside: talc deposits frequently sit in rocks that also host tremolite and actinolite, and asbestos contamination of talc has been the basis of extensive litigation. Johnson & Johnson stopped selling talc-based baby powder in North America in 2020 and worldwide in 2023 amid tens of thousands of claims. Inhaling talcum powder is also a recognised respiratory hazard for infants independently of any contamination.
Where it comes from
Mined at large scale for paper, plastics, ceramics, paint and cosmetics. The asbestos contamination question turns entirely on deposit geology, and reputable suppliers test for it.
Historical use
Soapstone has been carved for at least five thousand years — Egyptian scarabs, Inuit sculpture, Indian temple carving, Chinese seals — because it is soft enough to work with almost any tool and hardens somewhat on firing. It is also used for laboratory benches and wood stoves, because it is chemically inert and holds heat.
Recorded as history and attributed where possible. That a stone was used for something establishes that people used it, not that it worked.
Worth knowing
Talc closes the Mohs scale at the soft end, opposite diamond, and it is the last entry in this collection for a reason worth stating.
It is not sold as a crystal. It carries no metaphysical reputation. It is the most ordinary mineral imaginable — the stuff of talcum powder, of soapstone carvings, of the filler in paper and paint — and it is the one on this list that has generated the largest volume of personal injury litigation in the history of any mineral.
The reason is entirely geological. Talc forms in the same rocks as tremolite and actinolite, and whether a given deposit is contaminated with asbestiform amphibole is a question about that particular body of rock. Nothing about the talc itself changed; the risk was always in what was next to it, and for decades nobody was required to look.
That is a reasonable note to end a collection of stones on. What a material is depends on what it formed with, what got trapped in it, what it was called and who was selling it — and the answer to "is this safe" is almost never a property of the name on the label.
Identity checked against IMA-CNMNC master list, June 2025.