300 PRISMATIC AMBLYGON SPAE. 



Comp. Ca2 Si + si aI + H = silica 44-41, 

 alumina 24-55, lime 26-74, water 4-30 = 

 100-00. 

 Analysis,frovci Dumbarton, by Walmstedt : 

 Silica . . . . . 44-10 

 Alumina .... 24-28 



Lime 26-43 



Protoxides of iron, manga- 

 nese, &c 74 



Water. .... 4-18 



99-71 



BB fuses to a blistered glass, with rapid 

 evolution of gas bubbles. 



Imperfectly acted on by acids ; but after 

 strong ignition or fusion, it is completely 

 decomposed by acids, with the formation of 

 a jelly. 



Localities. — English. Botallack Mine 

 and Huel Cock, Cornwall, in small, pale 

 green groups, in clay-slate, Ponck Hill, 

 Staffordshire. — Scotch. Bolan Quarry near 

 Old Kilpatrick, Dumbartonshire, in pale 

 greenish, mammillated concretions. Edin- 

 burghshire, at Samson's Ribs, Arthur's 

 Seat, in povphyritic greenstone; at the 

 Castle Rock, in basalt ; Costorphine Hill, 

 in greenstone. Leith, on the sea-shore. 

 Campsie Hills, Stirlingshire. Friskie Hall, 

 near Glasgow, of a fine sulphur -yellow 

 colour, in porphyritic greenstone. Hartfield 

 Moss, near Paisley, in Renfrewshire. Island 

 of Mull. Isle of Skye. — Irish. Mourne 

 Mountains, in white I'adiating concretions 

 in granite. — Foreign. St. Christophe, in 

 Dauphine, with Axinite and Epidote. 

 Fassa Valley, in the Tyrol, of a peculiar 

 bluish-green tint. The copper region of 

 Lake Superior, and in various parts of the 

 United States. China. Cape of Good Hope. 



Name. Named by Werner after Colonel 

 Prehn, a Dutch officer, by whom it was 

 first brought to Europe from the Cape of 

 Good Hope. 



Brit. Mus., Case 29. 



M. P. G. Horse-shoe Case, No. 1114. 



PrisjMAtic Amblygon Spar, 3Iohs. See 



AjilBLYGO^^ITE. 



Prismatic Ammoniac Salt, 3Iohs. 

 See Mascagnine. 



Prismatic Andalusitb, Mohs. See 

 Andalusite. 



Prismatic Antimony, Mohs. See Dis- 



CRASITE. 



Prismatic Antimony Baryte, 3Iohs. 

 See Valentinite. 



Prismatic Antimony Glance, 3Iohs. 

 See Sylvanite. 



PRISMATIC GYPSUM HALOID. 



Prismatic Arseniate of Copper, Bour- 

 non. See Olivenite. 



Prismatic Arsenical Pyrites, Mohs. 

 See MispiCKEL. 



Prismatic Augite Spar, Mohs. See 



WOLLASTONITE. 



Prismatic Axinite, Mohs. See Axi- 



NITB. 



Prismatic Azure Malachite, Mohs. 

 See AzuRiTE. 



Prismatic Azure Spar, Mohs. See 

 Lazulite. 



Prismatic Bismuth Glance, Mohs. 

 See Bismuthine. 



Prismatic Boracic Acid, Mohs. See 

 Sassolin. 



Prismatic Borax Salt, Mohs. See 

 Borax. 



Prismatic Calamine, Jameson. See 

 Smithsonite. 



Prismatic Cerium Ore, Jameson. See 

 Allanite. 



Prismatic Chrysolite, 3Iohs. See 

 Chrysolite. 



Prismatic Cobalt Mica, 3Iohs. See 

 Erythrine. 



Prismatic Copper Glance, Mohs. See 

 Copper-glance. 



Prismatic Copper Mica, Jameson. See 

 Chalcophyllite. 



Prismatic Corundum, 3Iohs. See 

 Chrysoberyl. 



Prismatic Cryone Haloid, Mohs. 

 See Cryolite, 



Prismatic Disthene Spar, Mohs. See 

 Cyanite. 



Prismatic Dystome Spar, 3Iohs. See 

 Datholite. 



Prismatic Emerald, Mohs. See Eu- 



CLASE. 



Prismatic Emerald Malachite, 

 3Iohs. See Euchroite. 



Prismatic Epsom Salt, 3Iohs. See 

 Epsomite. 



Prismatic Euchlore Mica, 3Iohs. 

 See Tyrolite. 



Prismatic Eutome Glance, 3Iohs. 

 See Sternbergite. 



Prismatic Fluor Haloid, Mohs, Hai- 

 dinger. See Herderite. 



Prismatic Gadolinite, 3'Iohs. See 

 Gadolinite. 



Prismatic Gar:set, Jameson. See 

 Staurolite. 



Prismatic Glauber Salt, 3Iohs. See 

 Glauber Salt. 



Prismatic Gypsum Haloid, Mohs. 

 See Anhydrite. 



