Chromio-pargasite is a striking, chromium-rich member of the amphibole supergroup characterized by its intense emerald-green hue. It is typically found in contact-metamorphosed dolomitic limestones and serpentinites, often forming sharp, short prismatic crystals that are highly sought after by collectors.
Is this chromio-pargasite?
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 chromio-pargasite with a known reference. Chromio-pargasite sits at Mohs 6, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: pale green.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: emerald-green, pale green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals.
Often confused with
Chromio-pargasite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside chromio-pargasite
Minerals reported to co-occur with chromio-pargasite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- NaCa₂Mg₄CrSi₆Al₂O₂₂(OH)₂
- Mohs hardness
- 6
- Density
- 3.08 g/cm³
- Colors
- Streak
- Pale green
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic crystals
- Cleavage
- Perfect on {110}
- Rarity
- Rare
- Uses
- Collector, Lapidary
- Host rock
- Along cracks in podiform chromitite deposits scattered in serpentinized dunite associated with rocks of the eclogite metamorphic facies; probably formed during retrograde metamorphism
Where rockhounds find chromio-pargasite
Classic worldwide localities
- Akaishi mine, Higashi-Akaishi Mountain, Ehime Prefecture, Japan
Field-hunting tip
Where it forms: Along cracks in podiform chromitite deposits scattered in serpentinized dunite associated with rocks of the eclogite metamorphic facies; probably formed during retrograde metamorphism. If you start seeing chromite, kämmererite, cr-poor clinochlore in float, you are in the right ground. Typical habit: prismatic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify chromio-pargasite?+
Where is chromio-pargasite found?+
What rocks look like chromio-pargasite?+
What minerals are found with chromio-pargasite?+
What kind of rock does chromio-pargasite form in?+
What is chromio-pargasite used for?+
Find chromio-pargasite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
