Columbite: The mineral columbite-tantalite information and picturesColumbite is the niobium-rich member, and Tantalite is the tantalum-rich member. . Other U.S. localities include the Ham and Weeks Mine, Wakefield, Carroll.columbite mining pdftantalite
,columbite mining pdftantalite,Occupational radiation exposures of artisans mining columbite .J Radiol Prot. 2007 Jun;27(2):187-95. Epub 2007 May 24. Occupational radiation exposures of artisans mining columbite-tantalite in the eastern Democratic.