Tyuyamunite, Selenium

This specimen features yellow sphereoids of tyuyamunite, a rare uranium mineral, accompanied by metallic black needles of native selenium. The vibrant, canary-yellow colouration of the metatyuyamunite is due to its high uranium content, which also makes the mineral slightly radioactive. In contrast, the jet-black, lustrous selenium needles add a striking visual contrast. Selenium, a native element and number 34 on the periodic table, is magnetic and forms these sharp needle-like structures on the matrix. This specimen hails from the Firefly-Pigmay Mine, a notable uranium mining site located in San Juan County, Utah. This combination of uranium-rich minerals and native selenium creates a visually stunning and scientifically significant specimen.