slgwv's photos with the keyword: calcite

Harder calcite (I think) veins weathering out of Aztec Sandstone. Valley of Fire State Park, Nevada, USA. The Aztec is correlative with the Navajo Sandstone of Utah and northern Arizona, but for historical reasons has a different name here. The calcite crystallized in cracks. You can tell this is a desert area, because the _calcite_ would weather first if the climate weren't so arid!

Havasu Creek, Grand Canyon, Arizona, USA. The water is saturated with calcium carbonate, which precipitates as travertine (a freshwater limestone) when agitated. This builds up these curious structures. Colloidal CaCO3 is also responsible for the curious turquoise color to the water.