Olivine
Olivine group
Common · (Mg,Fe)₂SiO₄
A magnesium iron silicate, one of the most abundant minerals of Earth's upper mantle. It alters readily: water turns it to serpentine, and weathering to iron oxides and clays. Found in basalts, gabbros and peridotites, and in stony-iron meteorites.
Identity
- Formula
- (Mg,Fe)₂SiO₄
- Chemical class
- Silicate
- Members
- Forsterite, Fayalite
- Mineral group
- Peridot
- Also known as
- Peridot (gem variety), Chrysolite (archaic)
Crystallography
- Crystal system
- Orthorhombic
- Habits
- Massive, Granular, Prismatic
- Fracture
- Conchoidal
Physical properties
- Mohs hardness
- 6.5
- Density
- 3.3 g/cm³
- Luster
- Vitreous
- Colors
- olive green, yellow-green, yellow, brown
- Streak
- white
- Transparency
- Transparent, Translucent
Geology
- Origins
- Igneous, Metamorphic
- Host rocks
- Volcanic rock, Ultramafic rock (peridotite, serpentinite)
- Associated minerals
- pyroxene, Spinel, Chromite, Magnetite
- Found in
- Basalt, Gabbro, Kimberlite, Peridotite, Kimberlite pipe
- Geography
- worldwide
Classification
- Rarity
- Common
- Gem quality
- No
Arcane properties
- Affinity
- Earth, Fire
- Effects
- Elemental earth, Warding
- Planar origin
- Material Plane
Sources
- Olivine. Mindat.org (Hudson Institute of Mineralogy).
- M. Pasero and others, IMA Commission on New Minerals, Nomenclature and Classification, The New IMA List of Minerals, updated September 2026. International Mineralogical Association (CNMNC), 2026.
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Forsterite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Fayalite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
- Forsterite: Mineral information, data and localities. mindat.org.
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