  Puffed-up laptop battery. 
Defective lithium laptop battery that puffed up to twice its normal thickness.  Here you can see a second one taken out of its outer casing: 
  
 
Source: Theodore Gray 
Contributor: Wolfram Research 
Acquired: 1 January, 2007 
Text Updated: 17 February, 2007 
Price: $100 
Size: 7" 
Purity: <5%
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