Saturday, 13 May 2017

Color-Change Bastnasite

Bastnasite is one of a few rare earth carbonate minerals and is a change color as well. Bastnasite gets its name from its type locality, the Bastnas Mine, Riddarhyttan, Sweden. Bastnasite has been found in karst bauxite deposits in Hungary, Greece and the Balkans.

Bastnäsite also occurs as very high quality specimens at the Zagi Mountains, Pakistan. Within the last few years, the locality at Zagi Mountain in Pakistan has provided collectors with some of the finest quality Bastnasite specimens.
Bastnäsite ore is typically used to produce rare earth metals. It is soft, 4 to 4.5 on the Mohs scale. The stone is often found included. 'Eye clean' examples are rare and valuable. The stone typically exhibits a color change showing an orange color in incandescent light, but a yellowish-green color under mercury-bearing light bulbs.