IMA Abbreviation (Whitney-Evans 2010)
En
→ Enstatite
Mg orthopyroxene
Standard symbol from American Mineralogist (Whitney & Evans, 2010). Used in thin-section labeling, phase diagrams, and IMA-style species records.
Mohs 5–6
Vickers (~) 540 HV
Knoop (~) 620 HK
Geological setting
Plutonic igneous
Element composition by mass
Formula: Mg₂Si₂O₆ · molar mass: 200.77 g/mol
| O | 47.81% | |
| Si | 27.98% | |
| Mg | 24.21% |
Computed from atomic weights (IUPAC 2021). Site-occupancy groups (Fe,Mn) split equally.
GroupPyroxene Group
Mohs Hardness
5–6
Enstatite sits at 5–6 on the Mohs scale — just hard enough to scratch glass.
Colors:
Streak
White
White
Crystal system
Orthorhombic
Orthorhombic
SilicatesSilicates (Inosilicates — Pyroxenes)
TL;DR · 1 min read
Enstatite (Mg₂Si₂O₆) is the magnesium end-member of the orthopyroxene group and a major rock-forming mineral in mantle peridotite, gabbro, and meteorites. Its name from Greek "enstates" (resistant) reflects its refractory nature.
Enstatite (Mg₂Si₂O₆) is the magnesium end-member of the orthopyroxene group and a major rock-forming mineral in mantle peridotite, gabbro, and meteorites. Its name from Greek “enstates” (resistant) reflects its refractory nature. Enstatite is one of the most common minerals in stony meteorites and is paired with forsterite in upper-mantle assemblages.