Lanthanite - Encyclopedia
Class : Carbonates, nitrates, borates
Subclass : Hydrated carbonates
Crystal system : Orthorhombic
Chemistry : (La,Ce)2(CO3)3 8H2O
Rarity : Rare to uncommon
Lanthanite is a group of hydrated carbonates, composed of three minerals linked together by solid solutions : lanthanite-(La), the most common mineral of the group, lanthanite-(Nd) and lanthanite-(Ce). Lanthanite-(La) is the dominant lanthanum pole, which commonly admits appreciable contents of cerium, and sometimes neodymium. It owes its name to this chemical composition. It is a rare secondary mineral present in contexts rich in rare earth elements, and as such a companion to allanite. Lanthanite forms thick lamellar to tabular crystals, more commonly colorless, white, pinkish or yellowish earthy or grainy masses.
Main photo : Lanthanite-(Ce) and malachite from Britannia Mine, Beddgelert, Gwynedd, Wales, UK © Steve Rust
Lanthanite in the World
Twinning
Twins on {101} are known.
Fakes and treatments
No fakes recorded for this mineral species.
Hardness : 2.5 to 3
Density : 2.76 to 2.84
Fracture : Irregular
Streak : White
TP : Translucent to transparent
RI : 1.520 to 1.613
Birefringence : 0.093
Optical character : Biaxial -
Pleochroism : None
Fluorescence : None
Solubility : Acids
Magnetism : NoneRadioactivity : None