Moqui Marbles, naturally occurring iron oxide concretions that arise from navajo sandstone. Very prevalent in the Escalante Grand Staircase National Monument (I have a small one of these that looks like iron balls formed together!
Scorodite crystal - Tsumeb Scorodite is a Holy Grail rare species from this famous and now-closed Tsumeb Mine. This is a gemmy and lustrous, sharply terminated, blue-green thumbnail crystal. Highly representative of the species and noted locale.
Fluorite on Quartz - De'an Mine, Wushan, Jiangxi Province, China Size: x x 3 cm. The octahedral crystals have a green core but bright purple edges. Forming a vertical line on a snow-white quartz-matrix the brilliant aesthetics of this specimen is