508 



MINERALOGY 



localities in North Carolina. It occurs at Amelia Court House, 

 Virginia, in a granite associated with rutile and hiddenite. Often 

 found in the gold gravels of the West, especially in Idaho. At 

 Arendal, Norway, it is inclosed in the red apatite crystals. 



APATITE 



Apatite. Fluo-phosphate of calcium, Ca 4 (CaF)(P0 4 ) 3 ; Ca = 

 55.5, P 2 O 5 = 42.3 ; Hexagonal ; Type, Hexagonal Equatorial ; 

 c = .7346 ; 0001 A 1011 = 40 18' ; 0001 A 1012 = 22 59' ; Com- 

 mon forms, c(0001), m (1010), x (1011) ; Twinning, doubtful; 

 Cleavage, basal imperfect ; Brittle; Fracture, uneven; H. = 5; 

 G. = 3.17-3.23 ; Color, shades of green, brown, and red, also white, 

 gray, and violet; Streak, white or pale; Luster, vitreous; a = 

 1.638; = 1.634; <o - = .004; Optically (-). 



B.B. Fuses with difficulty at 5. The powder moistened with 

 H 2 S0 4 yields a green flame in 0. F., or the nitric acid solu- 

 tion shows phosphoric acid 

 ammonium molyb- 

 The concentrated 

 solution yields 



General description. 

 Crystals are stout prisms 

 terminated with the pyra- 

 mid of the first order, or 

 with the pyramid in com- 

 bination with the base. 

 Combinations of the three 

 orders of prisms, which as 

 well as the etch figures fix 

 the symmetry, occur on 

 small, brilliant, colorless 

 crystals found in a chloritic 



schist, associated with epidote and adularia, in the Untersulz- 

 bachthal, Austria. All three orders of prisms are in combination 

 on small tabular crystals, with small prism faces striated parallel 

 to the vertical axis, occurring in veins associated with fluorite, 



with 



date. 



HNO 3 



white precipitate 



H 2 SO 4 (Ca).' 



a 

 with 



FIG. 513. Apatite from Templeton, Canada. 



