Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/98

From Wikisource
Jump to: navigation, search
This page has been proofread, but needs to be validated.


In small lancet-shaped crystals, opake and white, occasionally aggregated into a cellular mass; from Arkendale.
In transparent tabular bevelled crystals. Those from Dufton are very fine.
Of a milk white colour, not bevelled, set edgewise on quartz, blende, and galena; from Aldstone.
In 4-sided transparent prismatic crystals, acuminated by 2 planes set on the lateral planes; from a vein at Dukesfield.

A curious mineral is found in some of the Aldstone moor veins. It consists chiefly of indurated clay with a mixture of iron; is of a smoke-grey colour, very hard and sonorous, and is intersected by deep impressions of tabular crystals of heavy spar, which have in some unknown manner been decomposed.


Earthy Minerals.
Quartz.─Is found crystallized in 6-sided pyramids in most of the mines.
Asbetus.—Of a leek green colour, has been observed by Mr. Bigge in Melmerby scar, forming veins in a hard reddish brown rock resembling basalt, but not magnetic.

I am not informed of more than six mineral springs in the district of the lead-mine measures, and of these only two have attained any degree of celebrity. These are the springs of Gilsland and Wardrew, which were analyzed in 1799 by the late Dr. Garnet. The sulphuretted water issues from a thick bed comprising 3 distinct strata of shale, which is covered by several measures of sandstone, forming together a perpendicular cliff about 90 feet in height on the north bank of the little river Irthing. Two gallons and a half of water