Uraninite - Lookout No. 22 claim, Marshall Pass, Saguache County, Colorado, USA

UO₂

Uraninite from the Lookout No. 22 claim, located in Marshall Pass, Saguache County, Colorado, represents a significant example of primary uranium mineralization from one of the region’s historic mining localities. This deposit is known for producing dense, metallic-black Uraninite crystals, often embedded within a host rock matrix containing associated secondary uranium minerals. The high uranium content of these specimens makes them naturally radioactive, with strong Geiger counter readings. Some pieces may also feature secondary uranium minerals such as autunite or meta-autunite, which can exhibit fluorescence under UV light, adding to their visual and scientific appeal.

The Lookout No. 22 claim is part of the broader Marshall Pass uranium district, which saw active exploration and mining during the mid-20th century. Uraninite from this locality is valued by collectors for its historical significance and well-formed crystalline structures. These specimens provide insight into the geological processes that concentrated uranium in the area, making them highly desirable for both academic study and private collections. Whether as a display piece or for research purposes, Uraninite from Lookout No. 22 remains a fascinating example of Colorado’s rich uranium mining heritage.

Approx. specimen size: 30mm x 25mm x 15mm

Approx. specimen activity on an SE International Ranger EXP: 160 000 cpm