Hielscherite is a very rare member of the ettringite group typically found in volcanic xenoliths within the Eifel region of Germany. It commonly forms delicate, needle-like hexagonal prisms that can be difficult to distinguish from ettringite without chemical analysis. Collectors prize it primarily for its extreme rarity and unique geological occurrence.
Is this hielscherite?
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 hielscherite with a known reference. Hielscherite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Hielscherite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Hielscherite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: acicular to prismatic crystals.
Often confused with
Hielscherite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside hielscherite
Minerals reported to co-occur with hielscherite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- K₆Ca₃Si₂O₄(SO₄)₃(OH)₁₂·26H₂O
- Mohs hardness
- 2.5
- Density
- 1.79 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Hexagonal
- Crystal habit
- Acicular to Prismatic Crystals
- Cleavage
- Perfect On {10-10}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Xenoliths in Volcanic Rocks
- Typical price
- $50-300 per specimen depending on size and quality
Where rockhounds find hielscherite
Classic worldwide localities
- Ettringen, Germany
- Mayen, Germany
Field-hunting tip
Look in xenoliths in volcanic rocks country, the host setting where hielscherite typically forms. If you start seeing ettringite, thaumasite, afwillite in float, you are in the right ground. Field specimens usually show a acicular to prismatic crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify hielscherite?+
Where is hielscherite found?+
How much is hielscherite worth?+
What rocks look like hielscherite?+
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Find hielscherite on the map
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