Rutherfordine, UO2CO3, was synthetically prepared from schoepite, UO2(OH)(2). 2H(2)O and solid CO2 at 100 degrees C. Synthetic rutherfordine was transformed into compreignacite, K-2(UO2)(6)O-4(OH)(6) . 8H(2)O, its sodium analogue and UO3 . 0.8H(2)O. X-ray powder diffraction, thermal analysis and infrared spectroscopy data of, rutherfordine, compreignacite, its sodium analogue and UO3. 0.8H(2)O are given.