Gibbsite

Gibbsite / Hydrargillite Gibbsite, also known as Hydrargillite, is an aluminum hydroxide mineral that crystallizes in the form of tabular crystals, masses, tiny concretions, and a spherical botryoidal pattern. It can be found in a variety of colors such as green, white, blue, yellow, red, and even colorless. Gibbsite was named by John Torrey in honor of George Gibbs, a famed geologist, and mineralogist. George Gibbs influenced the mineral community heavily in the 1800s and had the finest mineral collection in the USA all the way up to the 1810s until it was purchased by Yale University. This mineral is found in an important commercial ore, Bauxite, which is the world's main source of Aluminum and Gallium.

You can find Gibbsite worldwide, with major localities including China, Norway, Brazil, Jamaica, and the U. S. A. Gibbsite is an important ore of aluminium in that it is one of three main phases that make up the rock bauxite. Gibbsite has three named structural polymorphs or polytypes: bayerite (designated often as but sometimes as doyleite, and nordstrandite.

Gibbsite can be monoclinic or triclinic, while bayerite is monoclinic. Doyleite and nordstrandite are triclinic forms. Crystal Monoclinic