Chalcedony Photos                  
Cochise College                                                                                                                
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Roger Weller, geology instructor                       

wellerr@cochise.edu

Chalcedony
last edited:  12/19/07    number of photos:  4
Chalcedony is a cryptocrystalline form of quartz, SiO_{2.                                 
The name chalcedony applies to all forms of agate, jasper, flint,
and chert, but is more recently used for white or light blue agate.}
Mineral information on quartz
hardness: 7

lectures on chalcedony
Chalcedony by Audrey LaClair

cabochons
chalcedony cabochons-blue:  A  B  C

chalcedony cabochons-white:  A

Photos are copyright free for non-commercial educational uses. 
Just credit photos to R.Weller/Cochise College.
copyright 2007-R.Weller

                                                                                                                                                           
Special note:
USA occurrences
Arizona
     west of Patagonia
     south of the Superstition Mountains
Nevada
     Eldorado Mountains, 10 miles north of Searchlight (desert roses)