Pyroxenite is an ultramafic igneous rock consisting essentially of minerals of the pyroxene group, such as augite, diopside, or hypersthene. It is generally dark in color and found as cumulate layers within large mafic-ultramafic complexes or as part of ophiolite sequences.
Is this pyroxenite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch pyroxenite with a known reference. Pyroxenite sits at Mohs 5-7, softer than the next harder reference, harder than the previous one.
- 2Read the textureLook at a fresh break with a hand lens. Grain size: Often very coarse, with crystals up to several centimetres.
- 3Pick out the mineralsComposition: Essentially pyroxenes such as augite, diopside, hypersthene, bronzite or enstatite; accessory olivine, feldspar, chromite and garnet. Identify the two or three most abundant grains.
- 4Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 5Match the color rangeCompare against the expected color range: dark green, brown, black.
Often confused with
Pyroxenite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside pyroxenite
Minerals reported to co-occur with pyroxenite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Mohs hardness
- 5-7
- Density
- 3.2-3.6 g/cm³
- Colors
- Luster
- Vitreous
- Transparency
- Opaque
- Rarity
- Common
- Uses
- Decorative, Architectural, Scientific research
- Host rock
- ultramafic igneous intrusions
- Grain size
- Often very coarse, with crystals up to several centimetres
- Composition
- Essentially pyroxenes such as augite, diopside, hypersthene, bronzite or enstatite; accessory olivine, feldspar, chromite and garnet
Where rockhounds find pyroxenite
Classic worldwide localities
- Bushveld Complex, South Africa
- Stillwater Complex, USA
- Oman Ophiolite
- Grenville Province, Canada
Field-hunting tip
Where it forms: ultramafic igneous intrusions. If you start seeing olivine, plagioclase, chromite in float, you are in the right ground.
Common questions
How do you identify pyroxenite?+
Where is pyroxenite found?+
What rocks look like pyroxenite?+
What minerals are found with pyroxenite?+
What kind of rock does pyroxenite form in?+
What is pyroxenite used for?+
Find pyroxenite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
