Jump to content

Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/35

From Wikisource
This page has been validated.
II. A Description of the Red Oxyd of Copper, the production of Cornwall, and of the Varieties in the form of its Crystal, with Observations on the Lodes which principally produced it; and on the Crystallization of the arseniated Iron.

By William Phillips, Member of the Geological Society.


The Mine called Huel Gorland, in the parish of Gwennap and county of Cornwall, is in a hill whereon is situated the town of St. Day, to which it is immediately contiguous eastward. In this mine there are seven lodes; one of tin, the others of copper; but as only three of the latter have produced the red oxyd of copper, it will not be important further to notice the others. These three lodes are known by the names of the North Lode, the Great Gossan Lode, and the Muttrell Lode. The latter, is that noticed by the Count de Bournon, as having produced the arseniate of copper, in a paper published in the Transactions of the Royal Society, in which he has so ably and scientifically described that mineral.

In the North Lode which runs eighty fathoms north of the Great Gossan Lode, the red oxyd of copper was occasionally found with fluate of lime; though, compared with the quantities produced by the other two lodes, very sparingly.

The Great Gossan Lode averages about four feet in width; the Muttrell Lode about three feet. The former runs eight degrees from the north of the west, meeting the latter, which runs four degrees from