FLUOR SPAR 



121 



Dif. Distinguished by its inferior hardness frorr beryl, it 

 being easily scratched with a knife ; by dissolving in acids 

 without effervescence from carbonate of* lime and other car- 

 bonates ; by its difficult fusibility, and giving no metallic 

 reaction before the blowpipe from phosphate ,pf lead and 

 other metallic species. Its phosphorescence is also an im- 

 portant characteristic. 



Obs. Apatite occurs in gneiss and mica slate, granular 

 limestone, and occasionally in ancient volcanic rocks. The 

 finest localities in the United States occur in granular lime- 

 stone. The crystals from the limestone of St. Lawrence 

 county, N. Y., are among the largest yet discovered in any 

 part of the world. One from Robinson's farm measured a 

 foot in length and weighed 18 pounds. But they are nearly 

 opaque and the edges are usually rounded. They occur with 

 scapolite, sphene, &c. Edenville and Amity, Orange county, 

 N. Y., afford fine crystals from half an inch to twelve inches 

 long. At Westmoreland, N. H., fine crystals are obtained in 

 a vein of feldspar and quartz ; also at Blue Hill bay in Maine. 

 Bolton, Chesterfield, Chester, Mass., are other localities. A 

 beautiful blue variety is obtained at Dixon's quarry, Wil- 

 mington, Delaware. 



The name apatite, from the Greek apatao, to deceive, was 

 given in allusion to the mistake of early mineralogists re- 

 specting the nature of some of its varieties. 



8. fluor spar — Fluorid of Calcium, Filiate of Lime. 



Monometric. Cleavage octahedral, perfect. Secondary $&~*C^ 

 forms, the following : 



Rarely occurs fibrous ; often compact, coarse or fine gran- 

 alar. Colors usually bright ; white, or some shade, of light 

 green, purple, or clear yellow are most common ; rarely 

 rose-red and sky-blue ; colors of massive varieties often 



How is apatite distinguished from beryl? how from carbonates? how 

 "rom phosphate of lead? What is said of the crystalline form and 

 cleavage of fluor spar? What is said of its colors and appearance? 

 I I. 



