[ Top ] [ Japanese ]

Preiswerkite

Year of discovery: 1980 (Geisspfad pass, Switzerland), 2007 (Japan)

Locality list: A locality of preiswerkite

• NaMg₂Al₃Si₂O₁₀(OH)₂
• [Na⁺][Mg²⁺₂][Al³⁺][(OH)₂|(AlSiO₅)₂]^8-

• Class: Trioctahedral < True mica group < Mica supergroup
• Class: Phyllo-Aluminosilicate - Hydroxide

• Na => K: Eastonite

• Mg₂ => LiAl: Ephesite

• Al₂ => MgSi: Aspidolite

• Color: Pale green, Colorless
• Streak: White
• Luster: Vitreous
• Diaphaneity: Translucent

• Cleavage: Perfect on {001} (1 plane)
• Hardness: 2.5
• Density: 3.0

• System: Monoclinic
• Group: 2/m, C2/m
• Lattice: a=5.2, b=9.0, c=9.8, β=100.4