Strange, partially melted zirconium lump. Perhaps sintered from a powder then mechanically worked? I'm not sure why someone would do that to zirconium, and I have not seen it in this form before. This sample came from an old collection assembled by Ron Hipschman, an old hand at the Exploratorium in San Francisco (my favorite science museum).
Source: Ethan Currens
Contributor: Ethan Currens
Acquired: 23 December, 2005
Text Updated: 19 November, 2007