ARGENTIFEROUS COPPER-GLANCE. 73 



ner in Hessia, and in several places in the county of Mans. 

 feld. It is found in those varieties of secondary limestone, 

 which have been called Rauchwacke and Asche, and is some- 

 times accompanied by, and intermixed with, prismatoidal 

 Gypsum-haloide. 



ARFVEDSONITE. 



SPAR. 



Arfvedsonite. BROOKE. Ann. of Phil. No. XXIX. p. 381. 

 PHILL. p. 377- 



Cleavage, a rhombic prism of 123 55', with bril- 

 liant faces. 

 Colour black. Sp. Gr. = 344, BROOKE. 



It resembles hemi-prismatic Augite-spar, and is general- 

 ly considered as a ferriferous variety of it. It accompanies 

 the dodecahedral Kouphone-spar from Greenland, and black 

 paratomous Augite-spar, with which it is grouped with pa- 

 rallel axes, in the same manner as amphibole and pyroxene 

 in several varieties of diallage. It has not been analysed, 

 but according to Mr CHILDREN (Ann. of Phil. XUII. p. 

 37.), it melts easily into a black globule, if exposed in the 

 platina forceps to the blast of the blowpipe. With borax 

 it gives a glass coloured by iron ; with salt of phosphorus 

 likewise, but paler, and becoming colourless on cooling ; a 

 dark grey silica skeleton remains undissolved. 



ARGENTIFEROUS COPPER-GLANCE. 



GLANCE. 



Argentiferous Copper-Glance. JAM. Syst. Vol. III. p. 551. 

 Man. p. 321. Sulphuret of Silver and Copper. PHILL. 

 p. 293. 



Massive : composition impalpable. 

 Fracture flat conchoidal, even. 



