talc; talcum
Mineralogy term for the soft mineral talc, used in powder form (talcum powder) and in various industrial applications.
Talc is a very soft mineral with a Mohs hardness of 1.
Talc is sometimes used in baby powder.
talcum powder
From Chinese 滑石 (huáshí), literally 'slippery stone', referring to the mineral's greasy feel.