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T 



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74 On Eupyrchroite of Crown Pointy N. Y". 



of New York, p. 240; but his specimens differ somewhat from 

 mine in their physical characters. It was named Eupyrchroite i 

 by Prof. Emmons in allusion to the beautiful emerald green light, ^ 

 which it gives out when thrown on heated iron, its phosphor- *^ 

 escence being nearly equal to that of the chlorophane fluor spar 



of Connecticut. 



The Eupyrchroite phosphorite occurs in botryoida! concretions, 



having a fibrous structure, and an ash-gray or bkiish gray color, 

 the concretions being made up of successive layers of different 

 shades of color. Their surface is frequently covered with a deli- 

 cate film of iron pyrites which scales off readily when scraped 

 with the knife. Its Sp. Gr. is 3-053. Hardness 4^. Before the 

 blowpipe phosphoresces with a green light at first, then gives the 

 intense brightness characteristic of lime salts. It glazes on the 

 surface at a high temperature, but does not melt. In the glass 

 tube it gives out water, which is acid, and corrodes the glass. 

 When thrown in powder on metal, heated nearly to redness, it 

 exhibits a brilliant emerald green phosphorescence. Larger frag- 

 ments decripitate strongly. 



During its solution in chlorohydric or nitric acid, it effervesces 



slightly, carbonic acid gas escaping. The quantity of this gas 



was accurately determined by the proper apparatus. In prepar- 

 ing the mineral for proportional analysis, each fragment was care- 

 fully examined with a lens, to ascertain that it was free from 

 accidental admixture with other minerals. It was reduced to im- 

 palpable powder by levigation, and dried at 212^ F., and weighed 

 while still warm. A sample of the mineral in coarse powder was 

 used in the determination of the water contained in it. In the 

 other steps of the analysis the methods as given by Rose were 

 pursued, and the following results were obtained. 



Lime, 



47-230 



Phosphoric acid, . . . 45-710 



Carbonic acid, . . , 1-21S 



1-554 



0-130 

 0-204 

 0-599 



Lime, 



Chlorine, 



Calcium, 



Fluorine, 

 Calcium, 



085 



i> 



Protoxyd of iron, • . . 2-000 



Water 



500 



* 



100 000 



lied 



difference, in the re-formation of phosphate of lime, after decom- 

 position of the precipitated mixed phosphate of lime and fluorid 

 of calcium, and its equivalent of calcium was deducted from the 

 lime obtained as a sulphate of lime. 



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