HYPERSTEN. |53 



experienced no change of colour, weight, or figure, by 

 calcination. Its component parts were 



Silex 37*5 Component 



parts of the 

 black. 



Alumine 41 



Oxide of iron 18'25 



Magnesia 0*5 



Oxide of Manganese • • 0*5 



97-75 

 The specific gravity of the red staurolite was 3 "765. Its 

 component parts 



Silex 27 of the red. 



Alumine 52*25 



Oxide of iron 18*5 



■ ■ — manganese •.•• 0*25 



98 

 Analysis of hypersten^ called Labrador hornblende. 



Mr. Haiiy was the first who distinguished this stone from Labrador 

 hornblende. He had classed it with the metalloid diallage, hornblende, 

 or our bronzite; but he has lately shown, that it differs 

 both from hornblende, and from the diallage, or smarag- 

 dite. He designates it under the name of metalloid reddish 

 brown lamellar hypersten. 



Its specific gravity I find to be 3'39. Before the blow- Spec grav. 

 pipe it is infusible, but its semirnetallic lustre is turned ^'^^'"'^ 

 blackish. If exposed to a red heat after trituration, the 

 powder, which was of a deep ashen gray, acquires a brown 

 red colour, and loses one per cent of its weight. 



The results of its analysis were Component 



Silex .^.. 54-25 ^'"^'- 



Magnesia 14 



Alumine 2*25 



Lime 1'5 



Oxide of iron 24'5 



Water 1 



Oxide of manganese, atrace 



97-5 



Analysis 



