A mineral form of hydrated aluminium hydroxide (Al(OH)3). It is named after the US mineralogist George Gibbs (1776–1833).
Geology and Earth Sciences
Mineral, Al(OH)3, that is a constituent of bauxite; sp. gr. 2.4; hardness 3; greyish-white; occurs as an alteration product of aluminium silicates in laterite and bauxite deposits.