Semimetals Native Elements, Tellurium

Native tellurium with sometimes a small amount of selenium, gold, iron, etc. hexagonal-rhombohedral. Crystals rare; usually minute hexagonal prism with rhombohedral terminations. Commonly massive, columnar to fine granular. Perfect prismatic eleavage. H. = 2-2.5. G. = 6.1 – 6.3 Metallic luster. Tin-white color. Gray streak. Wholly volatile B. B. Fusible at 12. On charcoal tinges reducing flame green and gives a white oxide coating. Heated with concentrated sulfuric acid gives deep red color to solution. A rear species, found usually associated with the rare tellurides of gold and silver. Occurs with sylvanite near Zalatna, Rumania; at various localities in Colorado. Tellurium has little commercial value.