Diopside is a common rock-forming pyroxene mineral that frequently appears in contact-metamorphosed limestones. Collectors look for its characteristic prismatic, often square-sectioned crystals and distinctive green hues, with the deep 'chrome-diopside' variety being especially prized for its vivid color.
Is this diopside?
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 diopside with a known reference. Diopside sits at Mohs 5.5-6.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Diopside leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Diopside typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, gray, green, yellow-green, dark green, black.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals, granular, massive.
Often confused with
Diopside vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside diopside
Minerals reported to co-occur with diopside. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaMgSi₂O₆
- Mohs hardness
- 5.5-6.5
- Density
- 3.22-3.38 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic Crystals, Granular, Massive
- Cleavage
- Good Prismatic At 87 and 93 Degrees
- Rarity
- Common
- Uses
- Collector, Gemstone, Lapidary
- Host rock
- Contact Metamorphosed Limestone and Dolomite
- Typical price
- $5-50 for small specimens, $100+ for large gem-quality crystals or chrome-diopside specimens
Where rockhounds find diopside
25 mapped spotsClassic worldwide localities
- Italy
- Canada
- Russia
- USA
- Madagascar
- Pakistan
U.S. states with diopside
Each link opens a state-specific list of mapped rockhounding spots that produce diopside.
Field-hunting tip
Look in contact metamorphosed limestone and dolomite country, the host setting where diopside typically forms. If you start seeing calcite, forsterite, grossular in float, you are in the right ground. Field specimens usually show a prismatic crystals, granular, massive habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Utah, New York, Vermont. Start trip planning there.
Common questions
How do you identify diopside?+
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Can I find diopside in the United States?+
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Find diopside on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
