Donpeacorite is a rare manganese-rich member of the orthopyroxene group, structurally distinct from its monoclinic counterparts. It is primarily found in metamorphosed manganese deposits where it forms yellowish-brown prismatic crystals or granular aggregates. Collectors usually seek specimens from historic Swedish manganese mines or the famous Franklin locality.
Is this donpeacorite?
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 donpeacorite with a known reference. Donpeacorite 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. Donpeacorite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Donpeacorite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, brown, yellow-brown.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: prismatic, massive, granular.
Often confused with
Donpeacorite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside donpeacorite
Minerals reported to co-occur with donpeacorite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Mn,Mg)MgSi₂O₆
- Mohs hardness
- 5-6
- Density
- 3.37-3.41 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Prismatic, Massive, Granular
- Cleavage
- Good On {110}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Metamorphosed Manganese Deposits
- Typical price
- $50-300 per specimen
Where rockhounds find donpeacorite
Classic worldwide localities
- Langban, Sweden
- Franklin, New Jersey, USA
- Jakobsberg, Sweden
Field-hunting tip
Look in metamorphosed manganese deposits country — that is the host setting where donpeacorite typically forms. If you start seeing rhondonite, jacobsite, hausmannite in float, you are in the right ground. Field specimens usually show a prismatic, massive, granular habit, so train your eye for that shape before scanning the outcrop.





