[ Top ] [ Japanese ]

Afwillite

Year of discovery: 1925 (Dutoitspan mine, South Africa), 1965 (Japan)

Locality list: 2 localities of afwillite

• Ca₃Si₂O₄(OH)₆
• [Ca²⁺₃][(HSiO₄)₂]^6-,2H₂O

• Class: Nesosilicate - Hydrate
• Electrical: Piezoelectric

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

• Habit: Prismatic, fibrous elongated to [010], Tabular on {100} and {201}
• Aggregate: Radial
• Striation: [010]

• Cleavage: Perfect on {101} and {100} (3 planes)
• Hardness: 3-4
• Density: 2.6

• System: Monoclinic
• Group: m, Cc
• Lattice: a=16.3, b=5.6, c=13.2, β=134.9

Etymology: Alpheus Fuller Williams (1874-1953) of Dutoitspan mine, South Africa