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462 TELLURIUM. It occurs in small and fine granular distinct concre tions. It is semihard, approaching to soft. It is rather brittle. It is easily frangible. It is heavy. Specific gravity, 5.723, Muller; 5.730, Kirwan; 6.115, Klaproth. Chemical Characters. Before the blowpipe it melts as easily as lead, emits a thick white smoke, and burns with a light green colour, and a pungent acrid odour, like that of horse-radish. When exposed to a low heat, it is converted into a yel lowish or blackish coloured oxide: by ari increase of temperature, it melts into a dark-brown or blackish co loured glass, in which gold grains are interspersed: at a still higher heat, the oxide is entirely volatilised. In concentrated nitric acid, it is converted into a yello'V oxide, and a small portion is dissolved, which is precipi tated in yellow flakes, on the addition of water. t Constituent Parts. Tellurium, - - 92.55 Iron , - - 7.20 Gokl > - - 0.25 100 Klaproth, Beit. b. iii- s, 8- Geognostic Situation. It occurs in veins in porphyry, along with iron pyrites and quartz. Geographic