Orthoclase
Orthoclase
Orthoclase, is an important tectosilicate mineral which forms igneous rock. It came from the Greek for “break straight”, and belongs to the feldspar family of minerals, which also include moonstone, amazonite, spectrolite and labradorite. Orthoclase is a transparent yellow feldspar resembling citrine quartz or yellow beryl and is primarily found in Madagascar. Orthoclase is often colorless or champagne-colored.
Orthoclase have a vitreous luster and resemble other feldspar minerals in crystal habit, methods of twining, and especially by having cleavage surfaces inclined to each other at an angle of 90 degrees, or nearly so. It is often white, gray or flesh-red in color and sometimes occurs as colorless crystals. All feldspars weather readily under the action of both atmospheric agencies and acidic surface waters, yielding a form of clay known as kaolin. Orthoclase is extensively used in the production of porcelain and glass.