Orthoclase

Part of speech: noun

Definitions

1. A mineral type within the feldspar group, notable for its crystalline form and commonly found in igneous formations, it is recognized for high potassium levels, diverse geometric shapes, and industrial relevance
2. This mineral, classified as part of the feldspar family, displays a unique crystal structure and is often located in igneous rock, appreciated for its potassium presence, various shapes, and importance in geology and industry
3. A type of silicate mineral belonging to the feldspar group, it is characterized by its distinct crystalline structure and high potassium content, commonly occurring in igneous rocks and valuable in various applications

Etymology: Orthoclase is named for a geometric property of its crystals rather than for anything about its chemistry. The "ortho" comes from Greek "orthos," meaning straight or right, and the "clase" element comes from Greek "klasis," meaning breaking or cleavage. Together the name describes a mineral that breaks along two cleavage planes that meet at a right angle, a feature that distinguishes it from other feldspars, whose cleavage planes sit at slightly different angles. The name was built from classical roots as a technical coinage, so it describes a physical trait the mineralogist could see when a crystal was split. Orthoclase is a potassium feldspar, and the word is used for that mineral specifically, not as a general term for feldspars.