Defcriptkn effome new Foffili, 195 



efcence. Before the blow-pipe It is infufible. It is found in Sweden, In the Sala filver- 

 mine in Weftermannland. I have liicewife difcovered it in Buoen, three quarters of a mile 

 diftant from Anen, in Norway, where it occurs in mafles, ftraight and thick foliated. 



IV. ICHTYOPHTALME. 

 The chief colour yellowifh-white. Luftre like mother-of-pearl, approaching to greafy. 

 This foflii is tranfparent. It fpecific gravity is 2.491. It fcratches glafs and eafily 

 admits of being filed ; affording a white powder of a rough feel. Its own fubftance feels 

 fmooth, but not very dry, and is as cold as quartz. It is very difficult to pulverize it. 

 Texture lamellar, of a more than triple croffing. When cryftallized the laminae arc 

 large; but they are fmall when the foffil is maffive, or exhibits a fplintery fradure. The 

 form of the cryftals cannot be determined, as they are very much concreted, and ftrongly 

 cohere with each other. The fragments of the tranfverfe fradlure are irregularly angular, 

 in fome inftances orbicular with {harp edges. When firft aded on by heat upon the char- 

 coal before the blow-pipe, it undergoes no change, not even with refpedl to its colour; 

 but in the more violent fecond heat the pointed edges run iato a white enamel. With 

 fulphate of lime (gypfum), the ichtyophtalme is infufible ; on the contrary, it runs, when 

 mixed with fluat of lime (fluor-fpar), into a femi-pellucid milk-white glafs, the fufion being 

 accompanied by a little effervefcence. This foffil occurs at Uton, in Sweden, and confifts 

 of filex and a little alumine, or argillaceous earth. 



V. COCCOLITE. 



As to colour, coccolite is mountain, grafs, and olive-green. Its luftre is vitreous and 

 refplendent. It is opaque, and its fpecific gravity is 3.316* It fcratches glafs, but excites 

 only a few fparks with tlie fteel. Its ftreak is grey, or greyilh-white 5 its texture broad 

 foliated, in which a fingle croffing of the laminae is obfervable. It is an aggregate of large 

 coarfe and fine grained, granular polyhedrons. Thefe grains appear in fome inftances to 

 be fhort quadrilateral columns, fliarpened at both ends, and having pyramidal termina- 

 tions joined to, or fuperimpofed upon, the lateral furfaces. This ftone is infufible b* 

 itfelf. With carbonate of pot-afli it fufes with effervefcence, and fwells to a frothy 

 fcoriaceous glafs, of a dirty olive-green colour ; and with borax it produces a pale-yellowifli 

 femi-pellucid glafs. It is met with in the iron-mines Hellefta and Affebro, in Sudermann- 

 land, as well as in Nerike, in Sweden, and likewife in a beautiful form in the Arendal 

 iron diftrids of Norway. 



VI. APHRIZITE. 



Colour black, fomewhat greyifti. External luftre vitreous, inclining to the glofs of fat; 

 internally a little refplendent. Aphrizite is opaque. Its fpecific gravity is 3.1481. It 

 gives fire with fteel, and cannot be filed ; is very brittle, and readily broken. Its texture 

 is compa<3:. The crofs fradlure is fmooth, a little. even, ipcliuing to the flat conchoidal ; 



C c 3 and 



