Uranocircite, is a hydrated phosphate of uranium and barium that is found, like many other secondary uranium minerals, in the superficial oxidation zones of deposits of this metal.  It owes its name to the uranium which composes it and from the Greek kirkos (falcon), in allusion to its place of discovery : Bergen, near Falkenstein in Germany (literally stone of the falcon).  Isostructural with autunite, it is much less frequent than the latter but there are terms of intermediate composition, barium replacing calcium. Very similar in appearance to autunite, uranocircite is presented in fine square millimeter lamellae, transparent to translucent, yellow-green to light green, united in scaly masses, fans or rosettes. Like autunite, it exhibits a strong green-yellow fluorescence under UV light. Dehydration to meta-uranocircite is common. It is a mineral that has no particular use.
 
This specimen finds it's way to me from Bergen, Germany