It forms red crusts, is insoluble in cold water, but is decomposed by boiling water.
The waters of Bahr-Assal are deeply impregnated with salt, which, in thick crusts, forms crescent-shaped round the banks - dazzling white when reflected by the sun.
This product melts at 86° C., and becomes anhydrous when heated to 110° C. The anhydrous compound can also be prepared, as hard crusts melting at 146°, by crystallizing concentrated aqueous solutions at 30 to 35°.
After a month or so the plates are converted to a more or less considerable depth into crusts of white lead.
Columbium trichloride, CbC1 3, is obtained in needles or crystalline crusts, when the vapour of the pentachloride is slowly passed through a red-hot tube.