Gibbsite

Gibbsite – Al(OH)3
Elements: Aluminum, Oxygen, Hydrogen
Class: Oxides – Hydroxides
Crystal System: Monoclinic
Hardness: 2.5-3
Calcite
Talc (1)Diamond (10)
A copper coin can scratch it.
Origin: Hongsheke Bauxite Deposit, Wenshan, Yunnan – China
Did you know?

Gibbsite is the main aluminum mineral in bauxite, the ore behind nearly all the world's aluminum. Yet before a cheap way to free the metal was found in 1886, aluminum was more precious than gold. Napoleon III is said to have saved his aluminum tableware for his most honored guests and given everyone else plain gold.