gibbsiitinä

Gibbsiitinä is a mineralogical term referring to the orthorhombic crystal form of aluminum hydroxide, Al(OH)3. This polymorph is distinct from other forms of aluminum hydroxide, such as bayerite, nordstrandite, and doyleite, which crystallize in different systems. Gibbsiitinä is characterized by its specific arrangement of aluminum and hydroxyl ions in a three-dimensional lattice.

This mineral is typically found in bauxite deposits, which are the primary ore for aluminum. It forms under relatively low-temperature and low-pressure conditions, often associated with weathering processes of aluminum-bearing rocks. Gibbsiitinä can occur as an alteration product of other aluminum minerals, such as feldspars and micas. In bauxite, it is often found alongside other aluminum hydroxides, clays, and iron oxides.

The physical properties of gibbsiitinä include its white to grayish color and a dull to earthy luster. It is a relatively soft mineral, typically with a Mohs hardness of around 2.5 to 3.5. While it is not as economically significant as the primary aluminum ore minerals like boehmite and diaspore in terms of direct aluminum extraction, its presence and abundance in bauxite can influence processing methods and ore quality. Understanding the different polymorphic forms of aluminum hydroxide, including gibbsiitinä, is important in the study of mineral formation, weathering, and the geology of aluminum deposits.