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Schorl (Photo) [abbr. Srl ]

Year of discovery: 1524 (World), 1885 (Japan)

Locality list: 243 localities of schorl

• NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄
• [Na⁺][Fe²⁺₃][Al³⁺₆][(OH)₃|OH|(BO₃)₃|(SiO₃)₆]^25-

• Class: Alkali-subgroup 1 < Alkali-tourmaline group < Tourmaline supergroup
• Class: Cyclosilicate (Single ring) - Borate - Hydroxide
• Magnetism: Paramagnetic (Weak)
• Electrical: Piezoelectric, Pyroelectric

• Polymorph: Luinaite-(OH) (Monoclinic)

• NaFe => []Al: Foitite

• Fe => Mg: Dravite
• Fe => Mn: Tsilaisite

• Fe₂ => LiAl: Elbaite

• OH => F: Fluor-schorl

• NaFe₃ => LiAl₂: Rossmanite

• NaAl => CaMg: Feruvite

• Fe(OH) => AlO: Oxy-schorl

• Fe₃(OH)₃ => Al₃O₃: Olenite

• Color: Black, Bluish black, Brownish black
• Streak: Gray, Pale blue
• Luster: Vitreous
• Diaphaneity: Translucent-Opaque

• Habit: Long prismatic

• Cleavage: Poor on {11-20} and {1011}
• Hardness: 7
• Density: 3.2

• System: Trigonal
• Group: 3m, R3m
• Lattice: a=16.0, c=7.2

Etymology: An old German mining term meaning "Unnecessary mineral".

Synonym: Schörl