Talc is the softest mineral on Earth. It feels smooth and slippery to the touch, almost soapy, and can be scratched with your fingernail. Scientists use a hardness scale from 1 to 10, and talc ranks as number 1, while diamond, the hardest mineral, ranks as 10.

When ground into a fine powder, talc becomes talcum powder, which people use to absorb moisture and reduce friction. You might have seen it in baby powder or in the chalk bags that rock climbers and gymnasts use to keep their hands dry. Artists use blocks of soft talc, called soapstone, for carving sculptures because it's so easy to shape.

Talc forms naturally in rocks deep underground where heat and pressure transform other minerals over millions of years. The largest talc deposits are found in countries like China, India, and Brazil.

Because talc is so soft and slippery at the microscopic level, it has many industrial uses too. Manufacturers add it to ceramics, paper, paint, and plastics to improve their properties.