KYANITE. 173 



The analyses of bucholzite and sillimanite give varying results, and 

 still they make but one species. Fibrolite is another variety of thia 

 mineral from the Carnatic. 



KYANITE. L \y-\ 



Triclinic. Usually in long thin-bladed crystals aggre- 

 gated together, or penetrating the gangue. The annexed 

 figure is a portion of one of these crystals. Crystals 

 sometimes short and stout. Lateral cleavage, dis- 

 tinct. Sometimes fine fibrous. 



Color usually light blue, sometimes white, or a 

 blue center with a white margin ; sometimes gray, 

 green, or even black. Luster of fiat face a little 

 pearly. H=5 — 7. Rather brittle, but less so than 

 Sillimanite. Gr=3'6— 3.7. 



Composition : silica 37*0, alumina 63*0. Unaltered alontj 

 before the blowpipe. With borax forms slowly a transparent 

 colorless glass. 



Dif, Distinguished by its infusibility from varieties of 

 the hornblende family. The short crystals have some re- 

 semblance to staurotide, but their sides and terminations are 

 usually irregular ; they differ also in their cleavage and 

 luster. 



Obs. Found in gneiss and mica slate, and often accom- 

 panied by garnet and staurotide. 



Occurs in long-bladed crystallizations at Chesterfield and . ^ 

 Worthington, Mass. ; at Litchfield and Washington, Conn. ; yjT^- 

 near Philadelphia ; near Wilmington, Delaware ; and in 

 Buckingham and Spotsylvania counties, Va. Short crystals 

 (sometimes called improperly fibrolite) occur in gneiss at 

 Bellows Falls, Vt., and at Westfield and Lancaster, Mass.'/ 



In Europe, transparent crystals are met with at St. Goth- 

 ard in Switzerland, and in Styria, Carinthia, and Bohemia. 

 Villa Rica in South America, affords fine specimens. 



The name kyanite is from the Greek kuanos, sky-blue. 

 It is also called sappar, a corruption of sapphire ; also dis- 

 thene, and when white, rhcctizite. 



Uses. Kyanite is sometimes used as a gem, and has 

 some resemblance to sapphire. 



Wtzrihite. Resemhles kyanite, but gives off water before the blow- 

 pipe. It may be an altered kyanite. From St. Petersburg. 



Describe kyanite] What is the origin of the name? For what il 

 it used ? 



15* 



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