PHYSIOGRAPHY. 293 



Zircon. 



Pon I =131 49'. (prisme. H.) Fig. 492. The prima- 

 ry having both the edges and angles of the base truncated. 

 (dioctaedre. H.) Fig. 493. P on u =152 8'. u on /= 

 159 17'. (quadrisexdccimal H.) Fig. 494. P on x = 

 150 5'. / on x =142 55'. x on x =147 12'. (plagie- 

 dre. H.) Fig. 495. (binoiriunitaire. H.) 



Irregular forms and grains. 



Cleavage, parallel with P and /, the latter more distinct ; 

 but rather perfect. Surface, t and s rough. The other 

 faces are mostly smooth and shining. 



Lustre, more or less perfectly adamantine. Color red, 

 brown, yellow, grey, green, white ; excepting some red 

 tints, none of them bright. Streak white. Transparent to 

 translucent. 



Hardness =7-5. Sp. gr. =4-505. 



1. Before the blow-pipe, it lo^es its color but does not melt. 



2. Analysis. 

 By BERZELIUS. 



Silica . . . 33-62 . . . 3330 



Zirconia . . . 66.38 . . . 66-70 



3. Zircon is found in imbedded crystals in mountain masses, or in beds 

 included in them, from whence it is washed into the sand of rivers. 



4. It occurs with Epidole in the Saualpe in Carinthia, in sienite at 

 Frederiksvai n in Norway. In Ceylon, in France, at Bilin in Bohemia, 

 at Ohlapian in Transylvania, it occurs in the sand of rivers. 



The largest and most perfect crystals afforded by the United States, 

 have been found loose in the soil in Buncombe co. (N. C.) Handsome 

 crystals are tound in gneiss at Warwick, and in Magnetic Iron, at Mun- 

 roe, and in Scapolite at Edenville, (N. Y.) Crystals closely resembling 

 the variety from Norway, were found in loose masses of sienite at Mid- 

 dlebury, (Vt.) Large and handsome brown crystals occur in talcose 

 slate at Easton, (Penn ) Small but very perfect forms are met with at 

 Haddam, (Conn.) with Chrysoberyl, Garnet, &c. 



5. Zircon is sometimes used as a gem, but it is not much esteemed. 



25* 





