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 #3849 5803 X 2659 pixels
A combination of purple amethyst and white quartz; Africa Image #3830 3721 X 5979 pixels
Velvety soft blue masses of azurite are formed from the weathering of copper minerals. Used as a pigment by Renaissance painters. Image #3352 4800 X 3200 pixels
