Foliated or Plumbiferous Tellurium
- Nagyagerz. Emmerling II. 463. Werner.
- Tellure natif (var.) aurifère et plombifère. Haüy IV. 327.
- Tellure natif auro-plombifère. Haüy Tabl. 119.
- Tellure lamelleux. Bournon Catal. 447.
- Black Tellurium. Aikin, 141.
This variety of native Tellurium appears to be the most abundant, and at the same time the most impure; nevertheless it preserves, according to Bournon, to whom we are indebted for a full account of the crystals of all the varieties of Tellurium, the characters of the primitive form, and shews the structure of the crystals most perfectly. The primitive form of native Tellurium is not according to that acute crystallographer, an octahedron, as Haüy from imperfect specimens was led to conclude it to be, but a rectangular prism, whose height is to its width as 7 to 10.
Foliated Tellurium is found among Quartz, and pale rose-coloured Carbonate of Manganese in veins in porphyry, at Nagyag in Transylvania: it is sometimes accompanied by Yellow Tellurium, which is distinguished by its brittleness, and by Blende. The specimens represented are in the British Museum.
- * The Lead although considerable in quantity seems only to loosen the aggregation of the molecules of the Tellurium, without so combining with them as to form new molecules, and produce a specific distinction: it is probable, also, that the proportion is variable.