Yellowish green scales of liebigite on schist, from the Schwartzwalder Mine, Jefferson Co., Colorado. Liebigite is a secondary uranyl carbonate mineral that shows a brilliant blue/green fluorescent response under UV, most brightly under short wave. Being a uranium-containing mineral, liebigite is moderately radioactive. This specimen emits approximately 1500 cpm at 1 cm. This piece measures 39 x 38 x 21 mm, and weighs 42 grams.