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Anorthoclase (Photo) [abbr. Ano ]

Year of discovery: 1885 (Pantelleria island, Italy), 1910 (Japan)

Locality list: 112 localities of anorthoclase

• (Na,K)AlSi₃O₈
• (Na,K)[AlSi₃O₈]
• [(Na⁺,K⁺)][AlSi₃O₈]^-

• Class: Alkaline Feldspar subgroup < Feldspar group
• Class: Tecto-Aluminosilicate
• Insoluble in: HCl
• Radioactive: Very weak
• Stable above 700 degree

• (Na,K) => K: Orthoclase, Adularia, Microcline, Sanidine
• (Na,K) => Rb: Rubicline
• (Na,K) => Na: Albite, Kumdykolite, Lingunite

• (Na,K)Si => CaAl: Anorthite, Dmisteinbergite, Svyatoslavite
• (Na,K)Si => BaAl: Celsian, Paracelsian
• (Na,K)Si => SrAl: Slawsonite

• Color: White-Colorless
• Streak: White
• Luster: Vitreous
• Diaphaneity: Transparent

• Habit: Thick platy

• Cleavage: Perfect on {001} (1 plane), Good on {010} (1 plane)
• Hardness: 6-6.5
• Density: 2.6

• System: Triclinic
• Group: (-1), C(-1)
• Lattice: a=8.2, b=12.8, c=7.1, α=90.0, β=116.0, γ=90.0