Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/375

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of one of the varieties of this substance, of which I have never seen but two specimens; one in the collection of the late Mr. Greville, the other in my own. The bardiglione of these two fragments is of a light violet colour: it is intermixed with a great deal of actinote of a pale green colour, and of asbestos; as well as with a great number of small particles of yellow copper ore, of pyrites, and of magnetic iron ore, (fer oxydulé) which makes them act strongly on the magnetic needle. I have said, in No. 77 of the Journal des Mines, that I presumed, from the nature of the substances accompanying it, that this bardiglione came from Sweden or Norway. The specimen I have, was given to me about two years ago, with a positive assurance that it came from Sweden; but I could not gain any more particular information respecting the place.

M. Mohs, in the same catalogue, mentions two specimens of bardiglione of a similar texture, and of a smalt blue colour, one from Carinthia, the other from Swabia. This variety appears also in the violet bardiglione from the lead-mine of Pesai near Mont Blanc.

2. With large laminæ, very thin, and placed one upon another, so as to form separate and distinct aggregations. This variety, which is of a very beautiful white slightly inclining to blue, comes from Vulpino, a few leagues from Bergamo in Italy. Its laminæ are very thin, and placed one upon another, so as to form little separate aggregations, crossing each other in different directions, and giving the whole mass sometimes a lamellar, sometimes a fibrous appearance, according as the eye is directed toward the fiat sides of the laminæ, or their edges. This variety, which belongs to one of those of the stone known by the name of Marmo Barahglio di Bergamo, takes a very line polish, and has often a little admixture of quartz.

3. With small laminæ, in an uniform direction. This variety differs from that with large laminæ, only in regard to their size. I have a