Fluormayenite is a rare member of the mayenite supergroup often found in high-temperature contact metamorphic environments. It typically forms small, clear dodecahedral crystals associated with skarn minerals in ejected limestone blocks.
Is this fluormayenite?
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 fluormayenite with a known reference. Fluormayenite sits at Mohs 5.5-6, 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: colorless, rarely with greenish, yellowish tint.
- 5Look at form & habitCrystal system: cubic. Typical habit: dodecahedral crystals, massive.
Often confused with
Fluormayenite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside fluormayenite
Minerals reported to co-occur with fluormayenite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₁₂Al₁₄O₃₂F₂
- Mohs hardness
- 5.5-6
- Density
- 2.745 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Cubic
- Crystal habit
- Dodecahedral crystals, massive
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector, Scientific research
- Host rock
- Major constituent of larnite-bearing pyrometamorphic rocks
Where rockhounds find fluormayenite
Classic worldwide localities
- Jabel Harmun, near the Palestinian village of Nabi Musa, Judean Desert, Judean Mountains, West Bank, Palestinian Autonomy, Israel
Field-hunting tip
Where it forms: Major constituent of larnite-bearing pyrometamorphic rocks. If you start seeing larnite, shulamitite, ye’elimite in float, you are in the right ground. Typical habit: dodecahedral crystals, massive. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify fluormayenite?+
Where is fluormayenite found?+
What rocks look like fluormayenite?+
What minerals are found with fluormayenite?+
What kind of rock does fluormayenite form in?+
What is fluormayenite used for?+
Find fluormayenite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
