General Information:
Chemical Formula:
(La,Ce)2Al(SiO4)2(OH)
Composition:
(Molecular Weight = 506.57 gm)
Lanthanum 41.13 % La
Cerium 13.83 % Ce
Aluminum 5.33 % Al
Silicon 11.09 % Si
Hydrogen 0.20 % H
Oxygen 28.43 % O
Empirical Formula:
La1.5Ce0.5Al(SiO4)2(OH)
Environment:
Rare-earth ore deposits.
IMA Status:
Approved IMA 1987
Locality:
Bastnas mine, Riddarhyttan, Vastmanland, Sweden.
Name Origin:
Named for Alfred Ellis Tornebohm (1839-1911), former director of the Geological Survey of Sweden.
Physical Properties:
Color:
green or bright olive green.
Density:
4.94
Hardness:
4.5 - Between Fluorite and Apatite
Luster:
Adamantine - Greasy
More details...