mineral
Orthoclase Feldspar
KAlSi3O8 (Potassium Aluminum Silicate)
Hardness: 6 on Mohs scale; Color: Orange-peach to Salmon pink; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Cleavage: Two planes at 90 degrees; Specific gravity: 2.55-2.63.
- Hardness
- 6 on Mohs scale
- Color
- Orange-peach to Salmon pink
- Luster
- Vitreous to pearly
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Physical properties
Hardness: 6 on Mohs scale; Color: Orange-peach to Salmon pink; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Cleavage: Two planes at 90 degrees; Specific gravity: 2.55-2.63.
Formation & geological history
Commonly formed in igneous rocks such as granite, pegmatites, and syenites through the cooling of magma. It can also be found in metamorphic rocks like gneiss.
Uses & applications
Used in the manufacturing of glass, ceramics, and enamels. High-quality specimens like Moonstone are used in jewelry. Sometimes used as a mild abrasive.
Geological facts
Orthoclase is one of the ten defining minerals on the Mohs scale of mineral hardness. It is one of the most abundant minerals in the Earth's crust.
Field identification & locations
Identify in the field by its distinct salmon-pink or orange-peach color and its two planes of cleavage meeting at a right angle. It will scratch glass but not quartz.
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Metamorphic
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metamorphic
Gypsum (variety Selenite or Alabaster)
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Mineral
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Mineral/Rock
Granite
Granite (Phaneritic intrusive igneous rock)
igneous