Omphacite is a sodic-calcic pyroxene that serves as a defining mineral of eclogite, a high-pressure metamorphic rock. Collectors typically look for it as dark green, dense massive grains or subhedral crystals embedded in garnet-rich eclogite matrices.
Is this omphacite?
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 omphacite with a known reference. Omphacite 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. Omphacite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Omphacite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: green, dark green, blackish-green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: granular, massive, or prismatic crystals.
Often confused with
Omphacite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside omphacite
Minerals reported to co-occur with omphacite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Ca,Na)(Mg,Fe²⁺,Al,Fe³⁺)Si₂O₆
- Mohs hardness
- 5-6
- Density
- 3.29-3.43 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Granular, Massive, Or Prismatic Crystals
- Cleavage
- Good Prismatic Cleavage
- Rarity
- Uncommon
- Uses
- Collector, Geological Indicator
- Host rock
- Eclogite
- Typical price
- $10-50 thumbnail, $50-200 cabinet specimen
Where rockhounds find omphacite
Classic worldwide localities
- Norway
- Germany
- Italy
- USA
- Russia
Field-hunting tip
Look in eclogite country — that is the host setting where omphacite typically forms. If you start seeing garnet, kyanite, glaucophane in float, you are in the right ground. Field specimens usually show a granular, massive, or prismatic crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify omphacite?+
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How much is omphacite worth?+
What rocks look like omphacite?+
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Find omphacite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
