Talcum powder is a soft, silky powder made from a mineral called talc, one of the softest minerals on Earth. You might recognize it as baby powder, the white powder parents sometimes sprinkle on babies after baths to help keep their skin dry and prevent diaper rash.

Talc comes from rocks deep underground. When ground into a fine powder, it feels incredibly smooth and slippery between your fingers. This slipperiness makes it useful for absorbing moisture and reducing friction. Athletes sometimes dust their hands with talcum powder for better grip, and gymnasts apply it before grabbing bars or rings.

For over a century, talcum powder was a common household item. People used it after showers, sprinkled it in shoes to reduce odor, and even used it to help rubber gloves slide on more easily. However, scientists discovered that breathing in talcum powder repeatedly can irritate the lungs, so doctors now recommend using it carefully and keeping it away from babies' faces. Many parents today choose cornstarch-based powders instead, which work similarly but are often considered safer.