CRYSTALS OF ZIRCON. 57 



The phosphate of lime is slowly soluble in nitric 

 acid ; and occasions no phosphorescence when its 

 powder is thrown on burning coals. 



It is found at St. Anthony's nose, near New York, 

 in magnetic pyrites of a grey, sometimes bronze yel- 

 low color. This ore is partly in a state of decompo- 

 sition, having then the appearance of the brown 

 oxide of iron, the crystals which occur in this part 

 of the gangue have their edges generally blunted, 

 which is not the case with those found in the un- 

 altered pyrites; this would induce the belief that 

 these crystals have been partly dissolved by the sul- 

 phuric acid formed by the decomposition of the py- 

 rites. The crystals found in that part have always 

 a ferruginous color, while those in the undecomposed 

 part of the ore, are of a blackish green color. This 

 mineral, besides phosphate of lime, contains lamel- 

 lar hornblende of a dark green, when in the unde- 

 composed ore, and of a ferruginous color in the de- 

 composed parts. 



ZIRCON. 



Some well determined crystals of zircon occur on 

 the York road, near Philadelphia, exhibiting modi- 

 fications of the present known forms, which I shall 

 endeavour to describe. 



Zircon, (primitive form J Plate V. fig. 4. 



D1E12E2P 



Zircon pyramidal 1 



I s x P fig. 5. 



