Hedenbergite is an iron-rich member of the pyroxene group frequently found in contact-metamorphosed limestones. Collectors look for its dark, prismatic crystals or massive, granular aggregates typically embedded within skarn mineral associations.
Is this hedenbergite?
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 hedenbergite with a known reference. Hedenbergite 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. Streak: white green.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous or dull.
- 4Match the color rangeCompare against the expected color range: dark green, brownish green, gray green, grayish black, black.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: crystalline, granular, lamellar.
Often confused with
Hedenbergite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Hedenbergite leaves white green, Augite leaves gray-green.
How to tell apart: Streak differs, so Hedenbergite leaves white green, Johannsenite leaves greenish gray.
Often found alongside hedenbergite
Minerals reported to co-occur with hedenbergite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaFeSi₂O₆
- Mohs hardness
- 5.5-6.5
- Density
- 3.56 g/cm³
- Streak
- White green
- Luster
- Vitreous or dull
- Transparency
- Transparent to opaque
- Crystal system
- Monoclinic
- Crystal habit
- Crystalline, granular, lamellar
- Cleavage
- Good on {110}, (110) ^ (110) ~87°; partings on {100} and {010}
- Rarity
- Common
- Uses
- Collector
- Host rock
- A common constituent of metamorphosed iron formations or other ferruginous siliceous sediments; common in Fe-Mn skarns
Where rockhounds find hedenbergite
Classic worldwide localities
- Iron Hill, Gunnison Co., Colorado, USA
- Laxey mine, South Mountain, Owyhee Co., Idaho, USA
- Pima district, Pima Co., and the Westinghouse mine, Santa Cruz Co., Arizona, USA
- Hanover, Grant Co., New Mexico, USA
- Nordmark, Värmland, and Yxsjö, Örebro, Sweden
- Prägraten, Tirol, Austria
Field-hunting tip
Where it forms: A common constituent of metamorphosed iron formations or other ferruginous siliceous sediments; common in Fe-Mn skarns. If you start seeing grunerite, arfvedsonite, quartz in float, you are in the right ground. Typical habit: crystalline, granular, lamellar. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify hedenbergite?+
Where is hedenbergite found?+
What rocks look like hedenbergite?+
What minerals are found with hedenbergite?+
What kind of rock does hedenbergite form in?+
What is hedenbergite used for?+
Find hedenbergite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
