talcous

/ˈtælkəs/
adjective
  1. Containing or resembling talc; having a soft, powdery, or greasy texture.
    • The talcous rock felt smooth and slippery to the touch.
    • Geologists identified the talcous mineral by its soapy feel.
    • The artist used a talcous clay for her delicate sculptures.
Synonyms