Obsidian Photos
Cochise College
Photos of Rocks       
Igneous Rocks
Geology Home Page
Roger Weller, geology instructor                       

wellerr@cochise.edu    copyright 2011   


black obsidian-A
glassy igneous rock
The fragment of obsidian has a conchoidal (shell-like) fracture.

 

obsidian                                                                                                                                             1a

Photo is copyright free for non-commercial educational uses. 
Just credit photo to R.Weller/Cochise College.