Pyroxene is a major group of rock-forming silicate minerals found extensively in igneous and metamorphic environments. They are distinguished from similar amphiboles by their characteristic two cleavage planes that intersect at nearly 90 degrees.
Is this pyroxene?
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 pyroxene with a known reference. Pyroxene sits at Mohs 5-6, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white to gray.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous to dull.
- 4Match the color rangeCompare against the expected color range: black, dark green, brown, gray.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals, granular, massive.
Often confused with
Pyroxene vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside pyroxene
Minerals reported to co-occur with pyroxene. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- XY(Si,Al)₂O₆
- Mohs hardness
- 5-6
- Density
- 3.2-3.6 g/cm³
- Colors
- Streak
- White to gray
- Luster
- Vitreous to dull
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic crystals, granular, massive
- Cleavage
- Good in 2 directions at nearly 90 degrees
- Rarity
- Common
- Uses
- Collector, Petrology study
- Host rock
- igneous and metamorphic rocks
Where rockhounds find pyroxene
1 mapped spotsClassic worldwide localities
- Italy
- Germany
- Canada
- USA
- Norway
Field-hunting tip
Where it forms: igneous and metamorphic rocks. If you start seeing plagioclase, olivine, magnetite in float, you are in the right ground. Typical habit: prismatic crystals, granular, massive. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in New York. Start trip planning there.
Common questions
How do you identify pyroxene?+
Where is pyroxene found?+
Can I find pyroxene in the United States?+
What rocks look like pyroxene?+
What minerals are found with pyroxene?+
What kind of rock does pyroxene form in?+
What is pyroxene used for?+
Find pyroxene on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
