Roger Weller, geology instructor
firstname.lastname@example.org copyright 2012-R.Weller
fire opal within a lava ball-3
Boi Morto Mine, Pedro Segundo, Brazil
A bump on the smooth, outer surface of the lava ball has been eroded off,
showing the vesicular basalt below the surface.
This is a very unusual mode of occurrence for opal.
Photo is copyright free for non-commercial educational uses.
Just credit photo to R.Weller/Cochise College.
Opal specimen courtesy of Opex Opal
Specializing in precious opals and opal jewelry
P.O. Box 50548, Santa Barbara, California 93150