LIEBIGITE
Liebigite is a rare, radioactive, hydrous calcium
uranyl carbonate mineral, Ca2(UO2)(CO3)3·11H2O.
It has a nonmetallic, glassy to pearly luster, greenish-yellow color, pale
yellow streak, is fairly soft (H = 2.5 to 3), transparent to translucent,
brittle, and it fluoresces under ultraviolet light. Liebigite only forms
secondarily by alteration of rocks having other uranium minerals (such as
uraninite) and carbonates.
Liebigite (yellow) from the Schwartzwalder Mine, Jefferson County, Colorado,
USA.