122 



SALTS OF LfME. 



banded. The crystals are transparent or translucent. H=4. 

 Gr=3-14— 3-18. Brittle. 

 /^ Composition : fluorine 48*7, calcium 51*3. Phosphoresces 1 

 ' on a hot iron, giving out a bright light of different colorsv 

 in some varieties the light is emerald green ; in others, pur- 

 ple, blue, rose-red, pink, or an orange shade. Before the 

 blowpipe it decrepitates, and ultimately fuses to an enamel. 

 Pulverised and moistened with sulphuric acid, a gas is given 

 ^off which corrodes glass. 



The name chlorophane has been given to the variety that 

 affords a green phosphorescence. 



Dif. In its bright colors, fluor resembles some of the 

 gems, but its softness at once distinguishes it. Its strong 

 phosphorescence is a striking characteristic ; and also its 

 affording easily, with sulphuric acid and heat, a gas that cor- 

 rodes glass. 



IObs. Fluor spar occurs in veins in gneiss, mica slate, 

 clay slate, limestone, and sparingly in beds of coal. It is the 

 gangue in some lead mines. 

 Cubic crystals of a greenish color, over a foot each way, 

 have been obtained at Muscolonge Lake, St. Lawrence 

 county, N. Y. Near Shawneetown on the Ohio, a beautiful 

 purple fluor in grouped cubes of large size is obtained from 

 limestone and the soil of the region. At Westmoreland, 

 N. H., at the Notch in the White Mountains, Blue Hill Bay, 

 Maine, Putney, Vt., and Lockport, N. Y., are other locali- 

 ties. The chlorophane variety is found with topaz at Hun- 

 tington, Conn. 



In Derbyshire, England, fluor spar is abundant, and hence 

 it has received the name of Derbyshire spar. It is a common 

 mineral in the mining districts of Saxony. 



Fluorid of calcium is also found in the enamel of teeth, 

 in bones and some other parts of animals ; also in certain 

 parts of many plants ; and by vegetable or animal decompo- 

 sition it is afforded to the soil, to rocks, and also to coal beds 

 in which it has been detected. 



Uses. Massive fluor receives a high polish and is worked 



into vases, candlesticks and various ornaments, in Derbyshire, 



England. Some of the varieties from this locality, consisting 



f rich purple shades banded with yellowish white, are very 



What is said of the phosphorescence of calc spar? Of what does it 

 consist? What is chlorophane I How is finor spar dis'ingui.-hed t'rorn 

 the gems? What are i:s uses ? 



