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Here is a superb combination specimen of a Tantalum and Columbite crystal on matrix from the long closed Etta Mine near Keystone, South Dakota. This extraordinary piece has the very large Tantalum crystal that shows it’s dull dark color and interesting surface characteristics.  The attached lighter colored matrix appears to be comprised of Quartz and Sodaspar.  The outstanding specimen was originally one large Tantalum crystal, one of the largest we’ve ever seen, but has broken into several sections and glued back together.  The exceptional crystal measures 6 7/8″ x 5 1/2″ x nearly 1 5/8″ thick.  Overall the specimen is over 6 7/8″ x 6 7/8″ x 4 1/8″ and weighs a heavy 8 1/4 pounds.  This stunning specimen is an awesome work of nature.

In stock

SKU: GAL904 Category: Tags: ,


Tantalum is a gray, hard, rare, metallic element occurring in columbite and tantalite and usually associated with niobium: used, because of its resistance to corrosion by most acids, for chemical, dental, and surgical instruments and apparatus.  Columbite forms a series with the mineral tantalite.  In fact the two are often grouped together as a semi-singular mineral called columbite-tantalite in many mineral guides. The minerals of the Columbite/Tantalite families are difficult to distinguish from each other without sophisticated tests.  The combination is also called Coltan; short for columbite–tantalite and known industrially as tantalite.

Additional information

Weight9.00 lbs
Dimensions6.875 × 6.875 × 4.125 in

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