Fluorbritholite-(Ce) is a rare silicate mineral belonging to the apatite supergroup, characterized by its cerium-rich composition. It usually occurs as earthy or resinous brown masses in alkaline pegmatites and is often radioactive due to its rare earth element content.
Is this fluorbritholite-(ce)?
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 fluorbritholite-(ce) with a known reference. Fluorbritholite-(Ce) sits at Mohs ~5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: colorless to pale brown.
- 3Read the lusterHold the specimen under a strong light. Luster: adamantine.
- 4Match the color rangeCompare against the expected color range: yellow, tan, colorless, reddish brown.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: acicular, radial.
Often confused with
Fluorbritholite-(Ce) vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Fluorbritholite-(Ce) leaves colorless to pale brown, Apatite leaves white; luster reads adamantine on Fluorbritholite-(Ce) and vitreous on Apatite.
How to tell apart: Britholite-(Y) is the harder of the two (Mohs 6 vs. ~5); streak differs, so Fluorbritholite-(Ce) leaves colorless to pale brown, Britholite-(Y) leaves faint brown; luster reads adamantine on Fluorbritholite-(Ce) and resinous to dull on Britholite-(Y).
How to tell apart: Streak differs, so Fluorbritholite-(Ce) leaves colorless to pale brown, Monazite leaves white; luster reads adamantine on Fluorbritholite-(Ce) and resinous on Monazite.
Often found alongside fluorbritholite-(ce)
Minerals reported to co-occur with fluorbritholite-(ce). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₂Ce₃(SiO₄)₃F
- Mohs hardness
- ~5
- Density
- 4.66 g/cm³
- Streak
- Colorless to pale brown
- Luster
- Adamantine
- Transparency
- Opaque to translucent
- Crystal system
- Hexagonal
- Crystal habit
- Acicular, radial
- Cleavage
- Distinct on {0001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In vugs in nepheline syenite, marble xenoliths, sodalite syenite xenoliths, and pegmatite dikes (Mont Saint-Hilaire)
Where rockhounds find fluorbritholite-(ce)
Classic worldwide localities
- Mont Saint-Hilaire, Rouville County, Quebec, Canada (type locality)
Field-hunting tip
Where it forms: In vugs in nepheline syenite, marble xenoliths, sodalite syenite xenoliths, and pegmatite dikes (Mont Saint-Hilaire). If you start seeing analcime, microcline, aegirine in float, you are in the right ground. Typical habit: acicular, radial. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify fluorbritholite-(ce)?+
Where is fluorbritholite-(ce) found?+
Is fluorbritholite-(ce) safe to handle?+
What rocks look like fluorbritholite-(ce)?+
What minerals are found with fluorbritholite-(ce)?+
What kind of rock does fluorbritholite-(ce) form in?+
What is fluorbritholite-(ce) used for?+
Find fluorbritholite-(ce) on the map
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