| | |  Electrowinning plate. This is almost certainly a plate that came from the electrolytic extraction of cobalt from its ore, or from an electrolytic purification process.  Cobalt was dissolved in a solution and electricity was used to plate it out onto an electrode.  Very pretty, very heavy.
 Source: eBay seller akilawolf
 Contributor: Theodore Gray
 Acquired: 5 June, 2003
 Price: $15.50
 Size: 1.2"
 Purity: 99.9%
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