Adularia | |
Chemical Formula |
KAlSi3O8 |
Species |
Silicates |
Crystal System |
Monoclinic |
Mohs Scale |
6 |
Specific Gravity |
2.55-2.63 |
Color |
Colorless, Greenish, Grayish yellow, White, Pink |
Streak |
white |
Luster |
Vitreous, pearly on cleavage surfaces |
Refractive Index |
nα = 1.518–1.520nβ = 1.522–1.524nγ = 1.522–1.525 |
Diaphaneity |
Transparent to translucent |
Cleavage |
Has perfect cleavage on and good cleavage on . Cleavages intersect at 90°. It can be difficult to see cleavage in thin section due to orthoclase's low relief. |
Crystal Habit:Can be anhedral or euhedral. Grains are commonly elongate with a tabular appearance. |