The Collaborative International Dictionary of English v.0.48:

Brucite \Bru"cite\, n. [Named after Dr. A. Bruce of New York.]
   (Min.)
   (a) A white, pearly mineral, occurring thin and foliated,
       like talc, and also fibrous; a native magnesium hydrate.
   (b) The mineral chondrodite. [R.]
       [1913 Webster]