4G8 Do'taArN xVi. VOLCANIC. 



a porphyry with a base of felspar. It is found at 

 Lipari. 



" 3. Reddish grey amel, opake, with a stony 

 fracture, having some relation to what the Ger- 

 man mineralogists call porzellan jaspis ; but it is 

 incontestably an amel, since the greater part of the 

 specimens found at Lipari are perforated with, 

 pores, and in some parts vitrified; Whe'reas jas- 

 pers are infusible. 



" 4. A bluish grey amel, with a shining frac- 

 ture and an homogenous paste. 



" 5. A greenish amel, opake, shining, fracture 

 Vitreous with crystals of white felspar. When these 

 amels are cut and polished, the crystals are better 

 Observed. In this class I place the vitreous amel 

 of Puy Gryou, in Auvergne, formed in a large 

 current covered with lavas. M. de la Coste, 

 professor of the central school of Puy de Dome, 

 first pointed out this amel. 



" 6. An olive-green amel, of an homogenous 

 paste, and with a fracture of pitchstone, of Montfe 

 Galda in the Vicentin. 



" 7. An amel, of a homogenous paste, with 

 pitchstone fracture, of a 'pale black, with very fine 

 and undulating zones of a smoky grey, from Ascen- 

 sion Island. 



" 8. Vitreous amel, of a coal black or obsidian, 

 fracture irregularly conchoidal. I give the name 



