200 DESCRIPTIONS OF MINERALS. 



Yariscite {Peganite, Callainite) is another hydrous aluminum phos- 

 phate ; it is of a light green color, of various shades, to deep emerald- 

 green. From Montgomery County, Arkansas, and from Colorado ; also 

 from Messbach, in Saxon Voigtland. Fisclierite is a related mineral. 



Turquois. 



In opaque reniform masses without cleavage; of a bluish- 

 green color, and somewhat waxy lustre. H. = 6, G. — 2'Q 

 -2-8. 



Composition. Phosphorus pentoxide 32*6, alumina 46*9, 

 water 20*5 = 100. B. B. infusible, but becomes brown and 

 colors the name green ; soluble in hydrochloric acid ; moist- 

 ened with the acid it gives a momentary bluish green color 

 to the flame, owing to the copper that it contains. 



Biff. Distinguished from bluish-green feldspar, which it 

 resembles, by its infusibility and the reactions for phos- 

 phorus. 



Obs. Turquois is brought from a mountainous district in 

 Persia, not far from Xichabour ; and, according to Agaphi, 

 occurs in veins that traverse the mountain in every direc- 

 tion. 



The Callais of Pliny was probably turquois. Pliny, in 

 his description of it, mentions the fable that it was found 

 in Asia, projecting from the surface of inaccessible rocks, 

 whence it was obtained by means of slings. 



Turquois receives a fine polish and is highly esteemed as 

 a gem. In Persia it is much admired, and the Persian 

 king is said to retain for himself all the. large and more 

 finely tinted specimens. The occidental or lone turquois, 

 is fossil teeth or bones, colored with a little phosphate of 

 iron. Green malachite is sometimes substituted for turquois, 

 but it is of little hardness and has a different tint of color. 

 The stone is so well imitated by art as scarcely to be detected 

 except by chemical tests. The imitation is much softer 

 than true turquois. 



Childrenite. A hydrous phosphate containing aluminum, iron, with 

 little manganese. Found in trimetric crystals in Devonshire and 

 Cornwall ; also at Hebron in Maine. 



Eosphorite. Has the crystalline form and nearly the angles of chil- 

 drenite, and contains the same constituents, but differs in being 

 essentially a hydrous phosphate of manganese with little iron. From 

 Redding, Connecticut. 



Herucoodite is a hydrous aluminum phosphate from Cornwall, con- 

 taining also copper." 



