Closeup of a slab of Wild Fire Opal (with some agate) from Utah; Pleistocene in age (approx. 19,000 yrs old) Image #4074 4080 X 5884 pixels
Macro photograph of the detail in Birds Eye rhyolite; a rock of volcanic origin Image #2371 3200 X 4800 pixels
Blue masses of azurite are formed from the weathering of copper minerals. Used as a pigment by Renaissance painters. Image #2278 3033 X 4329 pixels
