  Corundum (aluminum oxide).  
Description from the source: 
Corundum (Al2 O3 trig.), India. Rough, complete, a bit deformed, as a horn. 4,5x2x1,8 cm; 34 g. 
Source: Simone Citon 
Contributor: John Gray 
Acquired: 26 September, 2008 
Text Updated: 28 September, 2008 
Price: Trade 
Size: 1.75" 
Composition: Al2O3
 |  
  |  
 |  
  |