Thorite orangite

Thorite and orangite (orange thorite) have a tetragonal structure and are isostructural with zircon. Steady-state spectra under X-ray and laser (337 nm) excitations are connected with REE " ", namely Sm " ", Tb ", Dy " " and Eu ". Reabsorption lines of Nd " have been also detected (Gorobets and Rogojine 2001). Laser-induced time-resolved luminescence enables us to detect Eu " and uranyl emission centers (Eig. 4.70). 

In 1851 Bergemannf announced the discovery of a new metal in orangite, the gem variety of thorite, and named it donarium. Subsequently, however, this was shown to be identical with thorium. In 1862 Bahr thought he had discovered in a mineral from Ronsholm a new metal which he named wasium, but two years later he himself showed that it was thorium. From experiments on the fractional distillation of thorium chloride Baskerville concluded in 1901 that two other elements were present, which he named berzelium and carolinium. In this he was mistaken. 

Representative time-resolved luminescence spectrum of zippeite, autunite, zeunerite, agate, orangite, thorite, monazite and xenotime are given in Fig. 4.170. 

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