Chalcedony Photos                  
Cochise College                                                                                                                
Photos of Gemstones
Translucent Gemstones

Geology Home Page
Roger Weller, geology instructor               

blue dyed chalcedony

last edited:  11/15/17    number of photos:  4
Chalcedony is a cryptocrystalline form of quartz, SiO2.                                 
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

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 2016-R.Weller

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