Reinhardbraunsite is a rare calcium silicate mineral belonging to the humite group, typically found as small, light pink grains within thermally metamorphosed limestone xenoliths. It is most notably associated with the Eifel volcanic region in Germany where it occurs in complex mineral assemblages formed by contact metamorphism. Due to its scarcity and similarity to other humite minerals, it is primarily a target for specialized mineral collectors.
Is this reinhardbraunsite?
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 reinhardbraunsite with a known reference. Reinhardbraunsite 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. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: light pink.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: granular to compact aggregates.
Often confused with
Reinhardbraunsite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside reinhardbraunsite
Minerals reported to co-occur with reinhardbraunsite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₅(SiO₄)₂(OH)₂
- Mohs hardness
- 5-6
- Density
- 2.85 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Granular to compact aggregates
- Cleavage
- Distinct on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In contact metamorphosed and metasomatized calcium-rich xenoliths in scoria
Where rockhounds find reinhardbraunsite
Classic worldwide localities
- Ettringer Bellerberg volcano, near Mayen, Eifel district, Germany
Field-hunting tip
Where it forms: In contact metamorphosed and metasomatized calcium-rich xenoliths in scoria. If you start seeing ellestadite, cuspidine, gehlenite in float, you are in the right ground. Typical habit: granular to compact aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify reinhardbraunsite?+
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What rocks look like reinhardbraunsite?+
What minerals are found with reinhardbraunsite?+
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Find reinhardbraunsite on the map
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