ORDER vi. PYliAMlDAL KOUPHONE-SPAR. 245 



though generally rather rough, and | P 4 ho- 

 rizontally streaked ; the vertical prisms, particu- 

 larly [P + oo] are streaked parallel to the axis. 



Lustre vitreous. The faces of P oo, both in 

 crystals, and as obtained by cleavage, possess 

 common pearly lustre. Colour, several shades 

 of white, greyish, blueish, or reddish, little dif- 

 ferent. Streak white. Transparent ... translu- 

 cent. 



Brittle. Hardness = 4-5 ... 5-0. Sp. Gr. = 2-335, 

 a crystallised variety from Iceland. 



OBSERVATIONS. 



1. The present species has not yet been sufficiently dis- 

 tinguished from the following one, and it is even possible 

 that they may constitute but a single one. It appears 

 that they do not differ in regard to chemical composition, 

 as will be seen in the Observations on the following species. 



2. The natural repositories of pyramidal Kouphone-spar 

 are much the same as 'those of the other species of the 

 present genus, either in the vesicular cavities of amygda- 

 loidal rocks with the same and with rhombohedral Lime- 

 haloide, or in metalliferous beds with prismatic Augite- 

 spar, rhombohedral Lime-haloide, Copper-pyrites, &c. 



3. Some of the finest varieties are found in the amygda- 

 loids of Iceland and of the Faroe islands. Likewise near 

 Indore in India. This is also the mode of its appearance 

 in nature near Aussig in Bohemia, whence the variety 

 called Albine has first been noticed, and in New South 

 Shetland. It occurs in the drusy cavities of a considerable 

 and very extensive bed of limestone in gneiss, containing 

 ores of copper, at Cziklowa near Orawitza in the Bannat. 

 It is difficult to decide, whether some of the localities 

 commonly quoted, belong to one or the other of these two 

 species. 



