Uraninite v. Pitchblende - Continental mine, Powder River Basin, Wyoming, USA

UO₂

Uraninite var. Pitchblende from the Continental Mine in the Powder River Basin, Wyoming, is a prime example of the rich uranium deposits that fueled the region's mining industry. This variety of Uraninite typically forms as dense, botryoidal or massive aggregates with a dark, pitch-black to brownish hue, giving it the characteristic appearance that led to the name "Pitchblende." The Powder River Basin is well known for its extensive uranium reserves, and the Continental Mine played a crucial role in supplying uranium during the mid-20th century. Specimens from this locality exhibit strong radioactivity and can be easily detected with Geiger counters or scintillation equipment, making them highly desirable for collectors of radioactive minerals.

The uranium deposits of the Continental Mine are hosted in the sedimentary formations of the Powder River Basin, where groundwater processes concentrated uranium over millions of years. Unlike crystalline Uraninite, Pitchblende from this mine often occurs as dense, amorphous to microcrystalline masses, sometimes associated with secondary uranium minerals such as autunite or carnotite. These specimens offer a glimpse into the geological processes that shaped Wyoming’s uranium-rich formations and remain significant both historically and scientifically. Whether for a serious mineral collection or as a teaching specimen, Pitchblende from the Continental Mine stands as a testament to Wyoming’s legacy in uranium mining.

Approx. specimen size: 65mm x 43mm x 40mm

Approx. activity on an SE International Ranger EXP: 209 000 cpm

Ex. Jack Nieburger Collection specimen.