Florencite-(La) is a rare phosphate mineral characterized by its small, often lustrous rhombohedral crystal forms. It is typically found in hydrothermal settings or as an accessory mineral in high-alumina metamorphic or sedimentary rocks. Collectors primarily seek out these specimens for their rare-earth element composition and interesting crystal morphology.
Is this florencite-(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 florencite-(la) with a known reference. Florencite-(La) 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: white.
- 3Read the lusterHold the specimen under a strong light. Luster: greasy to resinous.
- 4Match the color rangeCompare against the expected color range: colorless, light yellow.
- 5Look at form & habitCrystal system: trigonal. Typical habit: rhombohedral crystals.
Often confused with
Florencite-(La) vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads greasy to resinous on Florencite-(La) and earthy on Florencite-(Nd).
How to tell apart: Luster reads greasy to resinous on Florencite-(La) and resinous on Monazite.
Often found alongside florencite-(la)
Minerals reported to co-occur with florencite-(la). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- LaAl₃(PO₄)₂(OH)₆
- Mohs hardness
- ~5
- Density
- 3.52 g/cm³
- Colors
- Streak
- White
- Luster
- Greasy to resinous
- Transparency
- Transparent to translucent
- Crystal system
- Trigonal
- Crystal habit
- Rhombohedral crystals
- Cleavage
- Good on {0001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A secondary mineral in weathered metamorphosed corrensitic siltstone (Shituru deposit, Congo); an authigenic mineral in sandstone
Where rockhounds find florencite-(la)
Classic worldwide localities
- Shituru copper deposit, Likasi, Katanga Province, Congo (Shaba Province, Zaire)
- Bangombé natural fission reactor, Gabon
- Hamr, Stráž, and Holičky deposits, Czech Republic
Field-hunting tip
Where it forms: A secondary mineral in weathered metamorphosed corrensitic siltstone (Shituru deposit, Congo); an authigenic mineral in sandstone. If you start seeing synchysite-, manganoan siderite, sphalerite in float, you are in the right ground. Typical habit: rhombohedral crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify florencite-(la)?+
Where is florencite-(la) found?+
What rocks look like florencite-(la)?+
What minerals are found with florencite-(la)?+
What kind of rock does florencite-(la) form in?+
What is florencite-(la) used for?+
Find florencite-(la) on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
