Re: Are there any other gemstones which change color? on Jul 26 2007, at 12:09 in What gemstones change color like alexandrite?
Bastnasite, which is sometimes spelled as bastnaesite, is one of a few rare earth carbonate minerals and change color as well. Bastnasite gets its name from its type locality, Bastnas Mine, Riddarhyttan, Vastmanland, Sweden.
See interesting color change from orangy yellow to yellowish orange:
Although a scarce mineral and never in great concentrations, it is wide spread and one of the more common rare earth carbonates. Bastnasite has been found in karst bauxite deposits in Hungary, Greece and the Balkans