Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/290

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in the County of Wicklow; and I have observed it at Baltinglass hill, within a few miles of that place. I may mention here, that from the appearances of many specimens found in the neighbourhood of Killiney, Mr. Stephens was inclined to suppose that a connection existed between this singular species and Andalusite.

7. Pitchstone. This substance is found in a vein traversing granite, in the vicinity of Newry in the County of Down. I am indebted to Mr. Jameson of Edinburgh, for much of the following description of its external characters, as it appears there.

Its colour is intermediate between mountain and leek green. It is massive. Fracture small and not very perfect conchoidal.

Internal lustre, resino-vitreous and shining. It exhibits lamellar distinct concretions; the plates are from one-fourth to one-tenth of an inch in thickness, and are further divisible into pieces of the rhomboidal form of various angles.

The surface of the concretions is smooth, and strongly glistening. Slightly translucent on the edges. It scratches window-glass, but is easily scratched by quartz. Easily broken. Specific gravity, 2,29, Before the blowpipe without addition it yields a greyish-white frothy enamel.

It is in some places porphyritic, containing imbedded, minute crystals of feldspar and of quartz.

A letter from a very intelligent observer, who has examined this substance in its native place, states the following particulars respecting its position.

“ The vein is first observable in the Townland of Newry, at the bottom of a bank of granite, about half a mile from the northern end of the town, on the right of the road leading to Down-Patrick. It crosses the road, and runs due westward, ending on