Macro photograph of linear patterns in a Whitcomb Creek geode from Oregon; a geode is a stone nodule with an inner cavity filled with crystals or mineral matter Image #3286
Macro photograph of the detail in a piece of Birds Eye rhyolite; a rock of volcanic origin; #2369
Macrophotograph of a slab of magnesite (white) and hematite (red) from the Globe Copper Mine in Arizona Image #3908
