Columbite - Etta Mine, Keystone, South Dakota, USA
Columbite - Etta Mine, Keystone, South Dakota, USA
Fe2+Nb2O6
Here is one for you rare-earth collectors out there. A nice specimen of a partial Columbite crystal from the Etta Mine, Keystone, South Dakota, USA.
Approx. specimen size: 65mm x 40mm x 17mm
Approx. specimen activity: 150 cpm