Perry Petalite prospect, Peru, Oxford Co., Maine, USA

NaAlSi₃O₈

Crystal System: triclinic
Colour: white to grey, bluish, greenish or reddish
Lustre: vitreous
Habitus: tabular
Hardness: 6 - 6½
Fracture: irregular/uneven or conchoidal
Cleavage: perfect on {001}, good on {010}, imperfect on {110}
Density: 2.615(6) g/cm³ 
Origin and geological occurrence: it belongs to the feldspar group, in particular to the plagioclase series. Albite is one of the main constituent of granites and granite pegmatites, alkali diorites, basalts and hydrothermal and alpine veins. It may be the product of sodium metasomatism. It is a typical mineral of low-grade metamorphic rocks

www.mindat.org

Smorf link

Samples:

9F.4 Albite White compact masses associated with mica and quartz. #Tectosilicates