Microcline
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Microcline is an important igneous rock-forming tectosilicate mineral. It is a potassium-rich alkali feldspar. Microcline typically contains minor amounts of sodium. It is common in granite and pegmatites. Microcline forms during slow cooling of... Wikipedia
Luster: Vitreous
Hardness: 6–6.5
2V angle: 65–88°
Birefringence: Up to first order white (roughly 0.007)
Category: Tectosilicate
Color: White, grey, greyish yellow, yellowish, tan, salmon-pink, bluish green, green
Diaphaneity: Transparent, translucent