Rhombic. Cleavage (010) perfect.
G = 3·2-3·4. H = 3. Golden to bronze yellow; strongly pleochroic.
Brevik, Norway; El Caso Co., Colorado; Greenland.
Auerbachite.
An impure hydrated form of Zircon, ZrSiO₄. ZrO₂ = 55·2%.
Tetragonal; isotropic. Pseudomorphous after zircon.
G = 4·06. H = 6. Brownish-grey; translucent to opaque.
Alexandrovsk, Russia.
Auerlite.
3ThO₂,[3SiO₂,P₂O₅]6H₂O; traces of Fe, Ca, Mg, Al, CO₂, etc. SiO₂ replaced by P₂O₅3? ThO₂ = 69·2-72·2%.