Frankamenite is a rare silicate mineral primarily found in alkaline igneous complexes, occurring most notably in the Murun Massif of Russia. It typically appears as fibrous to acicular prismatic crystals that often exhibit a pale blue to white coloration.
Is this frankamenite?
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 frankamenite with a known reference. Frankamenite 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. Frankamenite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Frankamenite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, pale blue, pale yellow.
- 5Look at form & habitCrystal system: triclinic. Typical habit: fibrous, acicular, prismatic.
Often confused with
Frankamenite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside frankamenite
Minerals reported to co-occur with frankamenite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- K₃Na₃Ca₅Si₁₂O₃₀(OH,F)₂·H₂O
- Mohs hardness
- 5-6
- Density
- 2.71 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Triclinic
- Crystal habit
- Fibrous, Acicular, Prismatic
- Cleavage
- Perfect On {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Alkaline Igneous Pegmatites
- Typical price
- $50-300 per specimen
Where rockhounds find frankamenite
Classic worldwide localities
- Khibiny Massif, Kola Peninsula, Russia
- Murun Massif, Yakutia, Russia
Field-hunting tip
Look in alkaline igneous pegmatites country, the host setting where frankamenite typically forms. If you start seeing kalsilite, potassian feldspar, aegirine in float, you are in the right ground. Field specimens usually show a fibrous, acicular, prismatic habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find frankamenite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
