38 PHYSIOGRAPHY. 



Apophyllite. Arfwedsonite. 



Brittle. Hardness = 4' 5 . . . 5-0. Sp. gr. = 2-335. 

 Compound varieties. Massive : composition lamellar, 

 straight, or slightly curved. 



1. Before the blow-pipe, it first exfoliates, then intumesces like borax, 

 and melts at last into a white vesicular globule. It is easily dissolved 

 by borax. It is positively electrified by friction, but not by heat. It 

 likewise exfoliates in acids ; and its. powder forms with them, a jelly. 



2. Analysis. 



By BERZELIUS, By STROMEYER, 



fromUtoen. from Faroe. 



Silica . . 53-13 . . 52-38 . . 51-26 



Lime . . 24-71 . . 24-98 . . 25-20 



Potash . . 527 .. 5-27 . . 5-14 



Fluoric acid . 0-82 . . 0-64 . . 0-00 



Water . . 16-20 . . 1620 . . 16-04 



3. The natural repositories of Apophyllite are the vesicular cavities 

 of amygdaloidal rocks, or metalliferous beds with Augite, Calcareous 

 Spar and Copper Pyrites. 



4. Some of the finest varieties are from the amygdaloid of Iceland and 

 the Faroe islands. Likewise near Indore in India. Under similar cir- 

 cumstances it occurs at Mariaberg, near Aussig in Bohemia, and the va- 

 riety from thence has been called Jllbin. It has been found occupying 

 drusy cavities of a very extensive bed of limestone in gneiss, containing 

 ores of copper, at Czcklowa, near Oravvitza in the Bannat. Other local- 

 ities are New South Shetland, and several iron-mines in Sweden and 

 Norway. 



The only known localities in North America are Peter's Point and Par- 

 tridge Island in the Basin of Mines, Nova Scotia. 



ARFWEDSONITE. Peritomous Augite-Spar. 

 PARTSCH. 



Primary form. Oblique rhombic prism. M on M'= 

 123 55', from cleavage. 



Cleavage parallel with the sides of the prism/ producing 

 brilliant faces. 



