Eifelite is an exceptionally rare member of the osumilite group, typically found as microscopic prismatic crystals within volcanic rocks. It is most recognized from its type locality in the Eifel volcanic region of Germany, often occurring alongside sanidine and other volcanic minerals.
Is this eifelite?
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 eifelite with a known reference. Eifelite sits at Mohs 7.5-8 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Eifelite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Eifelite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, colorless.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: prismatic crystals.
Often confused with
Eifelite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside eifelite
Minerals reported to co-occur with eifelite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KNaMg₄Si₁₂O₃₀
- Mohs hardness
- 7.5-8
- Density
- 2.72 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Hexagonal
- Crystal habit
- Prismatic Crystals
- Cleavage
- Imperfect Basal
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Volcanic Ejecta
- Typical price
- $50-300 per specimen
Where rockhounds find eifelite
Classic worldwide localities
- Eifel Mountains, Germany
- Khibiny Massif, Russia
Field-hunting tip
Look in volcanic ejecta country — that is the host setting where eifelite typically forms. If you start seeing sanidine, augite, nosean in float, you are in the right ground. Field specimens usually show a prismatic crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find eifelite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
