enstatite
Sign in to saveEnstatite is a mineral; the magnesium endmember of the pyroxene silicate mineral series enstatite (MgSiO3) – ferrosilite (FeSiO3). The magnesium rich members of the solid solution series are common rock-forming minerals found in igneous and metamorphic rocks. The intermediate composition, , has historically been known as hypersthene, although this name has been formally abandoned and replaced by orthopyroxene. When determined petrographically or chemically the composition is given as relative proportions of enstatite (En) and ferrosilite (Fs) (e.g., En80Fs20).
Key facts
- Mineral.name
- Enstatite
- Mineral.category
- Inosilicate minerals (single chain)
- Mineral.group
- Pyroxene group, orthopyroxene subgroup
- Mineral.image
- Enstatite-202036.jpg
- Mineral.imagesize
- 260px
- Mineral.formula
- MgSiO3
- Mineral.IMAsymbol
- En
- Mineral.strunz
- 9.DA.05
- Mineral.system
- Orthorhombic
- Mineral.class
- Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m)
- Mineral.symmetry
- Pbca
- Mineral.unit cell
- a = 18.23, b = 8.84 c = 5.19 [Å]; Z = 8
- Mineral.color
- White, grey, green, yellow or brown - colorless in thin section.
- Mineral.habit
- Prismatic crystals, commonly lamellar, fibrous, or massive
- Mineral.twinning
- Simple and lamellar on [100]
- Mineral.cleavage
- Good/distinct on [210]
- Mineral.fracture
- Uneven
- Mineral.tenacity
- Brittle
via Wikipedia infobox
Article
6 sectionsContents
- Polymorphs and varieties
- Identification
- Occurrence
- In space
- See also
- References
Enstatite is a mineral; the magnesium endmember of the pyroxene silicate mineral series enstatite (MgSiO3) – ferrosilite (FeSiO3). The magnesium rich members of the solid solution series are common rock-forming minerals found in igneous and metamorphic rocks. The intermediate composition, , has historically been known as hypersthene, although this name has been formally abandoned and replaced by orthopyroxene. When determined petrographically or chemically the composition is given as relative proportions of enstatite (En) and ferrosilite (Fs) (e.g., En80Fs20).
==Polymorphs and varieties== thumb|left|Gem quality enstatite from Myanmar (size: 2.4×1.0×0.8 cm) Most natural crystals are orthorhombic (space group Pbca) although three polymorphs are known. The high temperature, low pressure polymorphs are protoenstatite and protoferrosilite (also orthorhombic, space group Pbcn) while the low temperature forms, clinoenstatite and clinoferrosilite, are monoclinic (space group P21/c).