9 Photos
Albite
Chemical Formula	NaAlSi3O8 or Na1.0–0.9Ca0.0–0.1Al1.0–1.1Si3.0–2.9O8
Species	Silicates
Crystal System	Triclinic
Mohs Scale	6
Specific Gravity	2.60-2.65
Color	White to gray, blueish, greenish, reddish; may be chatoyant
Streak	White
Luster	Vitreous
Refractive Index	n = 1.528 - 1.533 n = 1.532 - 1.537 n = 1.538 - 1.542
Diaphaneity	Transparent, Translucent
Cleavage	Perfecton , good on , imperfect on
Fracture	Irregular/Uneven, Conchoidal
Crystal Habit：Crystals commonly tabular, divergent aggregates, granular, cleavable massive
Geological Setting：A major constituent of granites and granite pegmatites, alkalic diorites, basalts, and in hydrothermal and alpine veins. A product of potassium metasomatism and in low-temperature and low-pressure metamorphic facies and in some schists. Detrital and authigenic in sedimentary rocks.

Albite is a felsic plagioclase feldspar mineral. It is the sodium endmember of the plagioclase solid solution series. As such it represents a plagioclase with less than 10% anorthite content. The pure albite endmember has the formula NaAlSi₃O₈. It is a tectosilicate. Its color is usually pure white, hence its name from Latin albus.

Albite crystallizes with triclinic pinacoidal forms. Its specific gravity is about 2.62 and it has a Mohs hardness of 6 - 6.5. Albite almost always exhibits crystal twinning often as minute parallel striations on the crystal face. Albite often occurs as fine parallel segregations alternating with pink microcline in perthite as a result of exolution on cooling.

It occurs in granitic and pegmatite masses, in some hydrothermal vein deposits and forms part of the typical greenschist metamorphic facies for rocks of originally basaltic composition.

It was first reported in 1815 for an occurrence in Finnbo, Falun, Dalarna, Sweden. The name is from Latin, albus for the typical white color.