Perbøeite-(La) is an extremely rare member of the epidote supergroup characterized by its high lanthanum content. It typically forms dark, prismatic crystals within syenite pegmatites and is primarily found in the Larvik Plutonic Complex of Norway. Due to its scarcity, it is sought after primarily by advanced collectors of rare-earth element minerals.
Is this perbøeite-(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 perbøeite-(la) with a known reference. Perbøeite-(La) sits at Mohs 6-7 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Perbøeite-(La) leaves a brown streak.
- 3Read the lusterHold the specimen under a strong light. Perbøeite-(La) typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: black, dark brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals.
Often confused with
Perbøeite-(La) vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Perbøeite-(La) leaves brown, Allanite leaves gray; luster reads vitreous on Perbøeite-(La) and submetallic on Allanite.
How to tell apart: Streak differs — Perbøeite-(La) leaves brown, Epidote leaves white.
How to tell apart: Streak differs — Perbøeite-(La) leaves brown, Perbøeite-(Ce) leaves white.
Often found alongside perbøeite-(la)
Minerals reported to co-occur with perbøeite-(la). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaLa₃Al₂Fe²⁺(Si₂O₇)(SiO₄)O(OH)₂
- Mohs hardness
- 6-7
- Density
- 4.15 g/cm³
- Colors
- Streak
- Brown
- Luster
- Vitreous
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Syenite Pegmatites
- Typical price
- $100-500 for quality specimens
Where rockhounds find perbøeite-(la)
Classic worldwide localities
- Sagåsen quarry, Norway
- Tvedalen, Norway
Field-hunting tip
Look in syenite pegmatites country — that is the host setting where perbøeite-(la) typically forms. If you start seeing quartz, microcline, aegirine 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 perbøeite-(la)?+
Where is perbøeite-(la) found?+
How much is perbøeite-(la) worth?+
What rocks look like perbøeite-(la)?+
What minerals are found with perbøeite-(la)?+
What kind of rock does perbøeite-(la) form in?+
What is perbøeite-(la) used for?+
Find perbøeite-(la) on the map
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