Green Oxide of Uranium: Pitchblende Fused with Soda, Cleared and Crystallised as Ammonium Uranyl Carbonate (Wöhler, Thorpe 1913)

Pitchblende is impure uranium oxide. Soda opens it up, acid dissolves the uranium, hydrogen sulphide throws out the heavy metals, and ammonium carbonate picks out the uranium alone. Ignited, the clean salt leaves the green oxide. Result: green oxide of uranium, U3O8, a dark-green radioactive powder. Source: Thorpe, Dictionary of Applied Chemistry vol. 5 (1913), pp. 585-586, after Wöhler. Not given: amounts and most temperatures. Hydrogen sulphide is a poison gas; the ore is radioactive. Picture drawn by Youblob.