  Corundum (aluminum oxide).  
Description from the source: 
Corundum (Al2O3 trig.), India. Partially levigated to highlight the cat's-eye effect. Purple-bluish color, very nice. 4x3x2 cm; 57 g. 
Source: Simone Citon 
Contributor: John Gray 
Acquired: 26 September, 2008 
Text Updated: 28 September, 2008 
Price: Trade 
Size: 1.6" 
Composition: Al2O3
 |  
  |  
 |  
  |