Fluocerite-(La) is a rare lanthanum-dominant fluoride mineral typically found in complex pegmatites and skarn deposits. It usually occurs as small, dull-colored masses or poorly defined crystals that are often radioactive due to trace impurities. Collectors value it as a scarce member of the fluocerite group.
Is this fluocerite-(la)?
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 fluocerite-(la) with a known reference. Fluocerite-(La) sits at Mohs 4-5, 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: greenish yellow.
- 5Look at form & habitCrystal system: trigonal. Typical habit: platy, tabular.
Often confused with
Fluocerite-(La) vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Fluocerite-(La) leaves white, Fluocerite-(Ce) leaves yellow white; luster reads vitreous on Fluocerite-(La) and waxy on Fluocerite-(Ce).
How to tell apart: Luster reads vitreous on Fluocerite-(La) and resinous on Monazite.
Often found alongside fluocerite-(la)
Minerals reported to co-occur with fluocerite-(la). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- LaF₃
- Mohs hardness
- 4-5
- Density
- 5.93 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Semitransparent
- Crystal system
- Trigonal
- Crystal habit
- Platy, tabular
- Cleavage
- “Dipyramidal”, imperfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In hydrothermal quartz veins in granite
Where rockhounds find fluocerite-(la)
Classic worldwide localities
- Zhanuzak area, Kent massif, Karaganda region, central Kazakhstan
Field-hunting tip
Where it forms: In hydrothermal quartz veins in granite. If you start seeing quartz in float, you are in the right ground. Typical habit: platy, tabular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify fluocerite-(la)?+
Where is fluocerite-(la) found?+
Is fluocerite-(la) safe to handle?+
What rocks look like fluocerite-(la)?+
What minerals are found with fluocerite-(la)?+
What kind of rock does fluocerite-(la) form in?+
What is fluocerite-(la) used for?+
Find fluocerite-(la) on the map
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