222 PHYSIOGRAPHY. 



Tabular-Spar. 



Lustre vitreous, inclining to pearly upon M and T. Co- 

 lor white, inclining to grey, yellow, red and brown. Streak 

 white. Semi-transparent . . . translucent. 



Rather brittle. Hardness = 4'0 ... 5*0. Sp. gr. = 

 2-805. 



Compound Varieties. Long individuals produce a re- 

 reticulated composition ; the composition apparently taking 

 place parallel with a plane in the direction of a, and inclin- 

 ing to T under about 140. (Grenville, Lower Canada.) 

 Massive : composition lamellar, generally longish, and ag- 

 gregated into a second large grained and angular composi- 

 tion. Strongly coherent. 



1. Before the blow-pipe, it melts on the edges into a semi-transparent 

 colorless enamel. It requires a strong heat for melting, and sometimes 

 boils a little. It is easily dissolved by borax, forming with it a transpa- 

 rent globule. By fusing lime and silica in the required proportions, 

 cleavable masses of the present species have been obtained. 



2. Analysis. 



By STROMEYER. By ROSE. 



Silica . . . 51-455 . . . 5160 



Lime . . . 47-412 . . . 46-41 



Protoxide of iron . . 0-401 . . . a trace. 



Oxide of manganese . . 0-257 . . . 00 



Water and loss by heating . 0076 . . . 000 



Mechanical admixtures . 0-000 . . . 1-11 



3. The oldest variety known is fiom Czcklowa near Orawitza, in the 

 Bannat of Temeswar, where it occurs in several copper mines. In Fin^ 

 land, it occurs in limestone ; at Edinburgh, in the greenstone of Castle- 

 hill. The variety called Wollastonite, from Capo di Bove near Rome, 

 occurs in lava, resembling basalt. A very handsome greenish white va- 

 riety, in large individuals, occurs in limestone bowlders at Grenville in 

 Lower Canada. 



In the United States are two localities; one at Willsborough, (N.Y.) 

 where the mineral forms the sides of a powerful vein of Garnet, which 

 traverses a mountain of gneiss : the other is at Easton in Pennsylvania, 

 where it exists in limestone. 



