  Twice-melted button. 
Description supplied by the source: 
This piece of tantalum is after the raw material has been melted into a special mold (melted on each side). It should still have basically the same purity (99.99%), which is also shown by the crystalline surface on the top and bottom. The company that manufactures these makes quite a few, apparently to be used as an anode in some special medical device. They would be machined after being melted, but to what dimensions or shape remains a mystery to protect the privacy of the customer. 
Source: Ethan Currens 
Contributor: Ethan Currens 
Acquired: 30 April, 2008 
Text Updated: 2 June, 2008 
Price: Anonymous 
Size: 1" 
Purity: 99.99%
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