sandstone - white to cream fine-grained Springdale Sandstone Member of the Moenave Formation, a unique silver ore - teaching hand/display specimen

The Springdale Sandstone is a geological oddity. In the Silver Reef Mining District in Washington County, Utah, this sandstone contained silver chloride. Silver Reef was the only major productive district of sandstone silver ores in the US and is one of the few places worldwide where sandstone contains silver. Silver chloride or chlorargyrite is inconspicuous and almost invisible in the sandstone. At Silver Reef, it constitutes the silver end-member of the oxidized carnotite deposits of the Colorado Plateau, where the carnotite is contained in Lower Cretaceous and Upper Jurassic sandstones. It was deposited in braided stream channels and minor flood-plain environments, and contains poorly preserved carbonized plant fragments. Copper mineralization introduced specks of azurite and malachite. The Early Jurassic Springdale Sandstone is a member of the Moenave Formation, though some geologists place it in the overlying Kayenta Formation, also Early Jurassic. The field photo shows the Silve