Macrophotograph of a piece of calcite and aragonite from the Sonoran Desert of Mexico Image #2272 3078 X 4617 pixels
Macrophotograph of the colors and patterns in a cut and polished slab of brecciated pink opal. An opalised radiolarite from Western Australia. Radiolarite is a sedimentary rock composed primarily of the microscopic skeletal remains of radiolara protozoa. Image #3842 3200 X 4800 pixels
