Macrophotograph of patterns in a thunderegg from Oregon. Thundereggs are nodule-like rocks found in lava flows. They develop within gas pockets in the lava as mineral deposits form within the cavity. Thunderegg is the Oregon State rock Image #3864
Macrophotograph of the branching linear patterns in a piece of Dead Camel jasper from Nevada Image #3911
Macro photograph of linear patterns in a polished slab of Snakeskin jasper from Western Australia, #3297
