Also visit Photos of Opals
for a more complete coverage on opals.
last edited: 11/22/10 number of photos: 5
Opal is SiO2.nH2O
common opal-tan color: 1
common opal-white: 1
boulder opal: 1
fire opal from Nevada:
synthetic opal: 1
Photos are copyright free for non-commercial educational uses.
Just credit photos to R.Weller/Cochise College.