Gibbsite
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Gibbsite, Al(OH)₃, is one of the mineral forms of aluminium hydroxide. It is often designated as γ-Al(OH)₃. It is also sometimes called hydrargillite.
Gibbsite is an important ore of aluminium in that it is one of three main phases that make up... Wikipedia
Chemical formula: Al(OH)3
Category: Hydroxide minerals
Crystal class: Prismatic (2/m); (same H-M symbol)
Crystal system: Monoclinic
IMA symbol: Gbb
Mohs scale hardness: 2.5–3
Space group: P21/n