About Orthoclase
A potassium-rich alkali feldspar, a polymorph of microcline and sanidine. Adularia is a variety (some moonstone is adularia). It's associated with hope, new beginnings, insight, and cooperation.
Primary Hues
Colorless, White, Grey, Pink, Yellow, Greenish, Reddish, often forms prismatic or tabular crystals
Geological & Scientific Details
Orthoclase is classified as a tectosilicate minerals, feldspar group, alkali series mineral which typically crystallizes in the monoclinic system. Its chemical formula is KAlSi3O8. Common crystal habits include can be anhedral or euhedral. grains are commonly elongate with a tabular appearance..
Key Geological Properties:
- Mineral Category: Tectosilicate minerals, feldspar group, alkali series
- Chemical Formula: KAlSi3O8
- IMA Symbol: Or[1]
- Crystal System: Monoclinic
- Predominant Geological Color: Colorless, greenish, greyish yellow, white, pink
- Crystal Habit: Can be anhedral or euhedral. Grains are commonly elongate with a tabular appearance.
- Twinning: Typically displays Carlsbad twinning. Baveno and manebach twins have also been reported in orthoclase.
- Cleavage: Has perfect cleavage on {001} and good cleavage on {010}. Cleavages intersect at 90°. It can be difficult to see cleavage in thin section due to orthoclases low relief.
- Luster: Vitreous, pearly on cleavage surfaces
- Streak: White
- Diaphaneity: Transparent to translucent