Interesting combo specimen which hosts two very rare selenites, Demesmaekerite and yellow Guilleminite. The Guilleminite is micro crystalline but the Demesmaekerite is present in well formed crystals: Some are free standing and reaching 1 mm. The combination is almost unheard of. The matrix is composed of Malachite and Selenium-rich Digenite. This mineral is the source of the selenites in Musonoi. This specimen was recovered during the removal of the U-dump in the early 90s. Musonoi has ceased producing minerals since then. NOTE THAT Musonoi is the TYPE LOCALITY for BOTH species.