orthoclase
/ˈɔːθəkleɪz
/noun [mass noun]
A common rock-forming mineral occurring typically as white or pink crystals. It is a potassium-rich alkali feldspar and is used in ceramics and glass-making.Feldspars are added as orthoclase in order to reduce the devitrification of the glass....
- Of these, alkali feldspar, particularly orthoclase, is the most common.
- Associated minerals are white orthoclase, milky quartz, and muscovite.
Origin
Mid 19th century: from ortho- 'straight' + Greek klasis 'breaking' (because of the characteristic two cleavages at right angles).