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Albite (Photo) [abbr. Ab ]

Year of discovery: 1815 (Catharina Neufang mine, Germany, and Finnbo, Sweden), 1895 (Japan)

Locality list: 1,019 localities of albite

• NaAlSi₃O₈
• (Na,K,Ca)Al(Si,Al)Si₂O₈
• [Na⁺][Al³⁺Si₃O₈]^-
• NaSi/(NaSi+CaAl)=0.5-1.0

• Class: Plagioclase series < Feldspar group
• Class: Tecto-Aluminosilicate
• Old definition was NaSi/(NaSi+CaAl)=0.9-1.0
• Variety: NaSi/(NaSi+CaAl)=0.7-0.9, Oligoclase
• Variety: NaSi/(NaSi+CaAl)=0.5-0.7, Andesine
• Insoluble in: HCl
• Magnetism: Diamagnetic
• Fluorescence: Short UV excitation (Blue), Long UV excitation (White-Orange)

• Polymorph: Kumdykolite (Orthorhombic), Lingunite (Tetragonal, High pressure)

• Na => (Na,K): Anorthoclase (Series, more than 700 degree)
• Na => Rb: Rubicline
• Na => K: Orthoclase, Adularia, Microcline, Sanidine

• NaSi => CaAl: Anorthite (Series), Dmisteinbergite, Svyatoslavite
• NaSi => BaAl: Celsian, Paracelsian
• NaSi => SrAl: Slawsonite

• Color: White, Pale blue, Pale green, Pale red
• Streak: White
• Luster: Vitreous
• Diaphaneity: Transparent-Translucent

• Habit: Tabular on {010}, Prismatic
• Aggregate: Foliate, Radial
• Twin: [010] (Albite twin)

• Cleavage: Perfect on {001} (1 plane), Good on {010} (1 plane), Indistinct on {110} (1 plane)
• Hardness: 6
• Density: 2.6

• System: Triclinic
• Group: (-1), C(-1)
• Lattice: a=8.2, b=12.9, c=7.1, α=93.5, β=116.4, γ=90.3

Etymology: Albus (White) in Latin