[ Top ] [ Japanese ]

Tephroite (Photo) [abbr. Tep ]

Year of discovery: 1823 (Sterling mine, USA), 1935 (Japan)

Locality list: 320 localities of tephroite

• Mn₂SiO₄
• [Mn²⁺₂][SiO₄]^4-

• Class: Olivine group
• Class: Nesosilicate
• Magnetism: Paramagnetic

• Mn => Zn: Willemite
• Mn => Mg: Forsterite(Series), Ringwoodite, Wadsleyite
• Mn => Fe: Fayalite (Series)
• Mn => Ca: Calcio-olivine
• Mn => Ni: Liebenbergite
• Mn => Be: Phenakite

• Mn₂ => CaMg: Monticellite
• Mn₂ => CaMn: Glaucochroite
• Mn₂ => CaFe: Kirschsteinite
• Mn₂ => LiAl: Eucryptite

• Color: Gray, Greenish gray. Brown
• Streak: Pale gray
• Luster: Greasy
• Diaphaneity: Translucent

• Habit: Fine grained
• Aggregate: Massive

• Cleavage: Distinct on {010} (1 plane), Imperfect on {001} (1 plane)
• Hardness: 6
• Density: 4.1

• System: Orthorhombic
• Group: mmm, Pnma
• Lattice: a=4.9, b=10.6, c=6.2

Etymology: Tephros (Gray) in Greek