|Electrochemically grown crystal.|
This beautiful man-made crystal was grown by electro-deposition from a salt solution. Presumably some kind of electrode was dipped in the solution and copper started growing on it under conditions that encouraged accretion at the ends rather than the sides of the dendrites. I believe these sorts of crystals are an unintended nuisance created during various electroplating operations, but they sure are pretty!
I have a very similar nickel crystal from the same seller.
Source: eBay seller judys-1000s-treasures
Contributor: Theodore Gray
Acquired: 22 February, 2003
Text Updated: 5 March, 2006