Fluor-tsilaisite is a very rare member of the tourmaline group, characterized by high manganese content. It is typically found in complex granitic pegmatites where it appears as distinct yellow to yellow-green prismatic crystals. Collectors prize it for its unique chemical signature and its role in understanding the evolution of manganese-rich tourmaline species.
Is this fluor-tsilaisite?
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 fluor-tsilaisite with a known reference. Fluor-tsilaisite sits at Mohs 7 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Fluor-tsilaisite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Fluor-tsilaisite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, yellow-green.
- 5Look at form & habitCrystal system: trigonal. Typical habit: prismatic crystals.
Often confused with
Fluor-tsilaisite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside fluor-tsilaisite
Minerals reported to co-occur with fluor-tsilaisite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na(Mn₁ꓐAl₆)(Si₆O₁₈)(BO₃)₃(OH)₃F
- Mohs hardness
- 7
- Density
- 3.1-3.2 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Prismatic Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector, Study
- Host rock
- Granite Pegmatites
- Typical price
- $100-500+ per specimen depending on size and clarity
Where rockhounds find fluor-tsilaisite
Classic worldwide localities
- Tsilaisina, Madagascar
- Elba, Italy
Field-hunting tip
Look in granite pegmatites country — that is the host setting where fluor-tsilaisite typically forms. If you start seeing quartz, microcline, albite 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
How do you identify fluor-tsilaisite?+
Where is fluor-tsilaisite found?+
How much is fluor-tsilaisite worth?+
What rocks look like fluor-tsilaisite?+
What minerals are found with fluor-tsilaisite?+
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Find fluor-tsilaisite on the map
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