تفروئیت
Sign in to saveTephroite is the manganese endmember of the olivine group of nesosilicate minerals with the formula Mn2SiO4. A solid solution series exists between tephroite and its analogues, the group endmembers fayalite and forsterite. Divalent iron or magnesium may readily replace manganese in the olivine crystal structure.
Key facts
- Mineral.name
- Tephroite
- Mineral.category
- Silicate mineral
- Mineral.image
- Tephroite Manganese silicate Kaao Mine Tochigi-ken Honshu Japan 1816.jpg
- Mineral.caption
- Tephroite from Japan
- Mineral.formula
- Mn2SiO4
- Mineral.IMAsymbol
- Tep
- Mineral.system
- Orthorhombic
- Mineral.class
- Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m)
- Mineral.symmetry
- Pnma (no. 62)
- Mineral.unit cell
- a = 4.88(2) Å, b = 10.61(2) Å c = 6.24(2) Å; Z = 4
- Mineral.color
- Olive-green, bluish green, gray, °esh-red, reddish brown; pale green in thin section, may be colorless
- Mineral.habit
- Crystals typically short, prismatic, to 4 cm, or anhedral, equidimensional. Commonly in disseminated grains, compact, or massive.
- Mineral.twinning
- Uncommon on {011}
- Mineral.cleavage
- {010}, distinct; {001}, imperfect
- Mineral.fracture
- Uneven to conchoidal
- Mineral.tenacity
- Brittle
- Mineral.mohs
- 6
- Mineral.luster
- Vitreous to greasy
via Wikipedia infobox