Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/374

 out a more or less considerable portion of their extent. This variety, as well as the preceding, is frequently observed among the crystals of bardiglione from Hall.

2. Fibrous. I have a small specimen of bardiglione from Hall, in which the crystals, which are very thin, extremely brittle, and nearly colourless, intersect each other in very different directions. In one of the parts of the specimen, this substance exhibits itself in divergent fasciculi, the fibres of which are of unequal lengths, and have a glistening lustre, which gives them an appearance that has considerable resemblance to that of the satiny coralliform arragonite. M. Mohs, in his catalogue of the splendid mineralogical collection of M. Von der Null of Vienna, mentions another variety of fibrous bardiglione, which he says came from Ischel in Upper Austria, and is of a colour intermediate between brick-red and blood-red.

3. Globular. To this variety I believe should be referred the globules of different sizes, from that of a poppy seed to that of a large pea, or still larger, which are met with in a rock of compact bardiglione mixed with sea-salt, known by the name of the Salt Rock of Arbonne, and situated at a very considerable height, being a very little distance from the region of perpetual snow near St. Maurice, in the vicinity of Mont Blanc. These globules are distinguishable from the compact bardiglione in which they are included, not only by their figure, but by their brown colour, that of the mass being grey, or reddish. Their substance is mixed in like manner with sea-salt. Their are much more fusible before the blowpipe.

Lamellar Bardiglione.

1. With large laminæ, lying in the same direction. Such is the texture