“Rocks” says a simple sign extending over the sidewalk on Ouray’s Main Street, adorned with a columbine flower. Inside, long narrow displays invite customers to explore toward the back, receding into Earth’s primordial history as they go. It’s like a natural history museum with all manner of shiny, colorful and jagged crystalline minerals, as well as dinosaur and shark teeth, leaf fossils, petrified wood, fossilized shells and trilobites.