534 MINERALOGY 



Brazil, the Philippine Islands, and in Maricopa County, Arizona, 

 where it is associated with vanadinite and wulfenite. 



FIG. 520. Crocoite from Dundas, Tasmania. 



Lead chromate is used as an oxidizer and as a pigment, but this 

 is the artificial salt, as crocoite is too scarce and not sufficiently 

 pure. 



KAINITE 



Kainite. MgSO 4 . KC1 . 3 H 2 O ; K 2 = 18.9, MgO = 16.1, 

 Cl = 14.3, S0 3 = 32.1, H 2 O = 21.8; Monoclinic; Type, Di- 

 gonal Equatorial; a:b: c = 1.2187: 1 : .5863; P = 85 6' = 

 001 A 100; 100 ,1 10 = 50 32'; 001 A 101 =24 43'; 001,011 = 30 

 18'; 111*111 = 54 1'; Common forms, a (100), b (010), c (001), 

 m(110), o(lll), o>(lll); Cleavage, a distinct, and b less so; 

 H. = 2.5-3; G. = 2.06-2.2; Color, white to dark flesh-red or 

 yellow; Streak, white; Luster, vitreous; Transparent to trans- 

 lucent; Optically (-); Axial plane, 010; Bx a A c = 10 45' in 

 front; 2V = 84 33'. 



B.B. Yields a potassium flame. Soluble in water, the solu- 

 tion yields a white precipitate with barium nitrate (BaSO 4 ), filtered 

 and acidified with nitric acid yields a white precipitate with silver 

 nitrate (Cl), or reacts for chlorine with copper oxide. Will not 

 effervesce with acids. Has a bitter, saline taste. 



General description. Crystals are combinations of the plus and 

 minus unit pyramids and prism, with the pinacoids at times. 



