Formula:  Mg(OH)₂

Species: Hydroxides

Colour: White, light greenish, grayish, bluish; honey-yellow, brownish red deep brown (manganoan varieties)

Lustre: Vitreous, Waxy, Pearly

Hardness: 2½ – 3

Specific Gravity: 2.39

Crystal System: Trigonal

Member of: Brucite Group

Name: Named in 1824 by François Sulpice Beudant in honor of Archibald Bruce, physician, early American mineralogist, and editor of the American Mineralogical Journal, who first described the species.

Type Locality: Castle Point, Hoboken, Hudson Co., New Jersey – USA