- a common white or pink mineral of the feldspar group, KAlSi3O8, having two good cleavages at right angles, and found in silica-rich igneous rocks: used in the manufacture of porcelain.
Origin of orthoclase
Examples from the Web for orthoclase
Historical Examples of orthoclase
In syenite and greenstone it occurs more commonly than orthoclase.Geology
If the initial composition of the magma is represented by a point between the two eutectic points, orthoclase will separate first.
This curve would represent the conditions under which orthoclase is in equilibrium with the molten magma.
The china-clay rocks of Cornwall and Devon are granites in which the orthoclase has become kaolinized.
The turbidity of orthoclase is usually due to partial kaolinization.
- a white to pale yellow, red, or green mineral of the feldspar group, found in igneous, sedimentary, and metamorphic rocks. It is used in the manufacture of glass and ceramics. Composition: potassium aluminium silicate. Formula: KAlSi 3 O 8 . Crystal structure: monoclinic
- A white to yellowish red monoclinic mineral of the potassium feldspar group that forms from medium- to low-temperature magmas. Chemical formula: KAlSi3O8.