Crystallized Quartz Enlarge
Dec. 1. 1806. Published by Ja.s Sowerby. London.
British Mineralogy
CXCIX
Silex Quartzum

Crystallized Quartz

  • Div. 1. Crystallized.

These curious specimens were lent me by Philip Rashleigh, Esq. of Menabilly, and are said to contain Arsenical Cobalt, They came from Poulteney mine, and are rare specimens, on account of the mine having been destroyed by the overflowing of a river. The Quartz is more regularly eighteen-sided than usual, although it is as it were clogged up with such abundance of a metal, that it otherwise would be nearly obliterated in its character; and that it should crystallize under such circumstances, distinctly and regularly at both ends, merely as if heaped on each other, as in the top figure, is very remarkable. There appears to be little else than Arsenical Iron among them, but capillary Silver and flowers of Cobalt are sometimes to be seen very distinctly about the gangue.

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