Feldspar

Feldspar is the collective term for the feldspar family of minerals, including orthoclase, sanidine, microcline, anorthoclase, plagioclase and celsian. Feldspar is the most important rock-forming mineral, and it occurs in the three main rock types, especially igneous rocks. It is also a main marker for rock classification. Feldspars rich in potassium or sodium are commonly used in the ceramic, glass and enamel industries. Feldspars with rare elements such as rubidium and caesium are good sources of these minerals. They are widely distributed in nature, but gem-grade minerals such as moonstone, amazonite, sunstone and labradorite are not common. The world’s highest quality moonstone is mainly mined in Myanmar, Sri Lanka and Switzerland. Sunstone mainly comes from Mexico, the United States and Norway. Labradorite mainly comes from Madagascar, Finland and Russia, and amazonite is produced in the United States, Russia and India. These stones are also mined in some areas of China....