The hardest mineral is, of course, diamond. The softest mineral is a whitish or grayish substance chemically known as magnesium silicate, but you have it in your bathroom and you know it as what?

The relative hardness of minerals is ranked on the Mohs scale, which runs from 1 (the softest) to 10 (the hardest). At the very bottom of this scale, with a hardness value of 1, is the mineral that serves as the correct answer. It is so exceptionally soft that it can be easily scratched by a human fingernail. This provides a stark contrast to diamond, which sits alone at the top of the scale with a perfect score of 10, making it the hardest known natural substance.

This soft, greasy-feeling mineral is a hydrated magnesium silicate, matching the chemical description provided. Its most famous household application is as the primary ingredient in talcum powder, often found in bathrooms to absorb moisture and reduce friction. The mineral is crushed into a fine white powder, giving us the product commonly known as baby powder or body powder. Beyond the bathroom cabinet, it is a surprisingly versatile industrial material used as a filler in the manufacturing of paper, plastics, and ceramics, and can also be found in paint and cosmetics.