482 



MINERALOGY. 



4>rjrctogno- Gengnostic and Geographic Situations. It occurs in 



s y- the salt mines of Bochnia and at Wieliczka in Poland. 



""Y"~ Observations It was first described as a variety of 



compact heavy-spar, and is by many named Pierre dc 



Tripes, from its convoluted concretions. 



FIFTH SUBSPECIES. 



COMPACT ANHYDRITE, Jameson. Dichter Muriacit, 

 Werner. 



Compact External Characters. Colours bluish-white, and tile- 

 anhydrite. re d. Sometimes with spotted delineations. Occurs 

 massive ; also in granular distinct concretions. Feebly 

 glimmering, or dull. Fracture small splintery, passing 

 into even and flat conchoidal. Fragments more or less 

 sharp-edged. Alternates from translucent to translu- 

 cent on the edges. 



Constituent Parts. Lime, 41.48 



Sulphuric Acid, 56.28 

 Water, 0.75100.00 



Rote, in Karsten's Tabellen. 



Geognostic and Geographic Situations. It occurs in 

 beds in the salt mines of Austria and Salzburg ; and 

 also in secondary gypsum, on the eastern foot of the 

 Hartz mountains. 



* VULPINITE. 



Vulpinite External Characters. Colour grey ish- white, and vein- 

 ed with bluish-grey. Occurs massive. Internally splen- 

 dent. Fracture foliated. Fragments rhomboidal. Oc- 

 curs in granular distinct concretions. Translucent on 

 the edges. Brittle. Easily frangible. 



Chemical Characters It melts easily before the blow- 

 pipe into a white opaque enamel ; and becomes feebly 

 phosphorescent when thrown on glowing coals. 

 Constituent Parts. Sulphate of Lime, 92.0 



Silica, 8.0100.0 



Fauquelin, in Bulletin des Sciences de la 



Societe Philomatique, N. 9- ', Journal 



de Physique, t. xlvii. p. 101.; Jour- 



nal des Mines, N. xxxiv. 



Geognostic and Geographic Situations. It occurs 

 along with granular foliated limestone, and is some- 

 times associated with quartz, and occasionally with 

 sulphur. It is found at Vulpino in Italy. 



Uses. 1. It takes a very fine polish, and is employ- 

 ed by the statuaries of Bergamo and Milan for making 

 slabs, chimney-pieces, &c. It is known to artists by 

 the name Marmo bardiglio di Bergamo. 2. It was first 

 particularly noticed by Fleuriau. 

 Glaubeiite. * GLAUBERITE. Glauberite, Brongniprt. 



External Characters. Colours greyish-white, and 

 wine-yellow. Occurs crystallized, in very low oblique 

 four-sided prisms, the lateral edges of which are 104 

 28' and 75 32', and in which the terminal planes are 

 set on obliquely. Crystals occur singly, or in groups. 

 Lateral planes transversely streaked ; the terminal 

 planes smooth. Shining. The fracture parallel with the 

 terminal planes and edges is foliated ; in other directions 

 it is conchoidal. Softer than calcareous spar. Trans- 

 parent. Brittle. Specific gravity 2.700. 



Chemical Characters. It decrepitates before the 

 blowpipe, and melts into a white enamel. In water it 

 becomes opaque, and is partly soluble. 



Constituent Parti. Dry Sulphate of Lime, - 49.0 

 Dry Sulphate of Soda, 51.0 



100.0 



Brongniart, J. ties Mines, t. xxiii. p. 17. 

 Geognostic and Geographic Situations. It is found 



imbedded in rock-salt at Villaruba, near Ocana in New Oryctogno- 

 Castile, in Spain. y. 



Observations. It was brought from Spain to Paris '*""Y'~' 

 by M. Dumeril, and first analyzed and described by 

 Brongniart. 



GENUS II CRYOLITE. 



Eis-Haloide, Mohs. 



One axis. Cleavage pyramidal. One perpendicu- CRYOLITE. 

 lar, cleavage and other two less perfect. Hardness 

 =25 3.0. Specific gravity=2.9 3. 



1. PYRAMIDAL CRYOLITE, Jameson. Pyramidales Pyramidal 

 Eis-Haloide, Mohs. cryolite. 



Pyramid unknown. The most perfect cleavage is par- 

 allel with the terminal planes of a rectangular four- sided 

 prism ; another less distinct, parallel with the diagonals 

 of a rectangular four- sided prism ; and a third, still 

 less perfect, parallel with the planes of the pyramid. 



External Characters. Colours pale greyish-white, 

 snow-white, yellowish-brown, and yellowish-red. Oc- 

 curs massive, disseminated, and in straight and thick 

 lamellar distinct concretions. It is shining, inclining 

 to glistening, and the lustre is vitreous, inclining to 

 pearly. Fracture uneven. Fragments cubical or ta- 

 bular. Translucent. Brittle, and easily frangible. 



Chemical Characters. It becomes more translucent 

 in water, but does not dissolve in it. It melts before 

 it reaches a red heat, and when simply exposed to the 

 flame of a candle. Before the blowpipe, it at first runs 

 into a very liquid fusion, then hardens, and at length 

 assumes the appearance of a slag. 

 Constit. Parts. Alumina, 24.0 21.0 



Soda, 36.0 32.0 



Fluoric Acid, 



and Water, 40.0 47.0 



100.0 100.0 



Ktaproth, Beit. Vauquelin, Hauy, 



b. iii. s. 214. Traitc, t. ii. p. 400. 



Geognostic and Geographic Situations. This curious 



and rare mineral has been hitherto found only in West 



Greenland, and but in one place of that dreary and 



remote region, viz. the Fiord or arm of the sea named 



Arksut, situated about thirty leagues from the colony 



of Juliana Hope, where it occurs in two thin layers in 



gneiss. 



GENUS III. ALUM-STONE. 



ALBM- 



STONE. 



Thon Haloide, Mohs. Alaunstein, Werner. 



One axis. Cleavage rhomboidal. Hardness = 5.0. 

 sp. gr. = 2.4. 2.6. 



1. RHOMBOIDAL ALUMSTONE, Jameson. Rhomboed- Rhomboi- 

 rishes Thon Haloide, Mohs. dai alum- 



Rhomboid unknown. The most distinct cleavage stone- 

 parallel with the sides of a rhomboid ; another, less dis- 

 tinct, parallel with the terminal plane of a six-sided 

 prism. 



External Characters. Colours white, pale flesh-red, 

 and more rarely pearl-grey and bluish-grey. Some- 

 times several of these colours occur together in spotted, 

 striped, and veined delineations. Occurs massive, some- 

 times porous, or nearly vesicular, with the walls lined 

 with small crystals. Internally it is dull, or feebly 

 glimmering. Fracture coarse, small grained uneven, 

 which passes into splintery, earthy, and flat conchoidal. 

 Fragments indeterminate angular, and rather sharp- 

 edged. Feebly translucent on the edges. Brittle and 

 easily frangible. 



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