Feldspars are a group of minerals that have similar characteristics due to a similar structure. All feldspars have low symmetry, being only monoclinic. They tend to twin easily and one crystal can even multiply twinned on the same plane, producing parallel layers of twinned crystals. Crystals tend to be blocky. Some feldspars may be triboluminescent. Feldspars also tend to crystallize in igneous environments, but are also present in many metamorphic rocks.

Uses of Feldspar
Major uses for feldspar are in the manufacture of glass and ceramics. In glasss making, feldspar provides alumina for improving durability, hardness, and resistance to chemical corrosion. In ceramics, feldspar is used as a flux because it lowers the vitrifying temperature of a ceramic object during firing and forms a glassy phase.