Lanthanite-(La) is a rare hydrated lanthanum carbonate mineral typically found as a secondary weathering product in rare-earth-rich deposits. It usually appears as delicate, pearly-lustered platy crystals or soft crusts, often requiring careful handling due to its fragility.
Is this lanthanite-(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 lanthanite-(la) with a known reference. Lanthanite-(La) sits at Mohs 3, 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 to pearly.
- 4Match the color rangeCompare against the expected color range: white, colorless, yellowish, yellowish white, pink.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: earthy, granular.
Often confused with
Lanthanite-(La) vs. its common look-alikes, and how to tell them apart in the field.
All properties
- Chemical formula
- La₂(CO₃)₃·8H₂O
- Mohs hardness
- 3
- Density
- 2.61 g/cm³
- Streak
- White
- Luster
- Vitreous to pearly
- Transparency
- Semitransparent
- Crystal system
- Orthorhombic
- Crystal habit
- Earthy, granular
- Cleavage
- {010}, perfect, micaceous
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare secondary mineral typically formed by alteration or weathering from earlier rare-earth-element-bearing minerals
Where rockhounds find lanthanite-(la)
Classic worldwide localities
- Found in lower Saucon Township, Northampton Co., Pennsylvania, and at the Scovill iron mine, Salisbury, Litchfield Co., Connecticut, USA
- Originally described from the Bastnäs mine, near Riddarhyttan, Västmanland, Sweden
- Thought to be lanthanum-rich but a recent analysis, not on type material, shows Ce > La, Sweden
- Curitiba, Paraná, and at Santa Isabel, São Paulo, Brazil
- Niikoba, Saga Prefecture, Japan
Field-hunting tip
Where it forms: A rare secondary mineral typically formed by alteration or weathering from earlier rare-earth-element-bearing minerals. If you start seeing allanite- in float, you are in the right ground. Typical habit: earthy, granular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify lanthanite-(la)?+
Where is lanthanite-(la) found?+
What rocks look like lanthanite-(la)?+
What minerals are found with lanthanite-(la)?+
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Find lanthanite-(la) on the map
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