Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/287

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Kilranelagh; and, as at that place, are accompanied by quartz, often of a similar greenish colour; with the addition however of bluish grey granular limestone, and a fibrous substance, not improbably tremolite, mixed with carbonate of lime. I have not seen any felspar in the specimens from Donegal.[1]

2. Grenatite. (Staurotide, Haüy). This was detected by Mr. Stephens in crystals in a micaceous compound of which I found a specimen at the Glenmalur lead mines in the County of Wicklow; the crystals are small, but their colour, form, and characteristic crossing are very distinct, and they are in fusible before the blowpipe.

3. Beryl. (Var. of Emerald, Haüy). The precious beryl has been found by Mr. Stephens and myself imbedded in granite, near Lough Bray in the County of Wicklow. (Museum of Dublin College, No. 39.) Mr. Weaver has discovered it in blocks of granite, near Cronebane in the same county; and I have found in the Dublin mountains above Dundrum, specimens probably belonging to the same species.

4. Andalusite. (Feldspatb apyre, Haüy). This has been found by Mr. Stephens and myself, in very distinct specimens, on the north-east side of Douce mountain in the County of Wicklow, apparently imbedded in the mica slate of which that mountain is composed, and accompanied by quartz, mica, and a remarkable crystallized substance hereafter to be mentioned. It differs from the Andalusite of Spain and of Scotland, chiefly by inferior hardness; for although some pieces scratch window-glass, others yield easily to the knife: but the Count de Bournon has observed an equal variation in the hardness of specimens of this substance found by him at Forez;[2] and I have found that of the Scottish stone to vary very much.

  1. Since this paper was written, I have found that this compound from Donegal has been described by Mr. Sowerby. British Mineralogy, August, 1810. p. 133.
  2. Journal de Physique, xxxiv. p. 453. 1789.