sri.l'lIATI.S. CHROMATliS, l.n 



turmeric paper. Fused with soda an<| a little coal dust in R. F. 

 yields a sulphur read inn on silver. Insoluble in acids. 



General description. Crystals are tabular parallel to the base, 

 when they are combinations of m, c, o, and d. The perfect cleav- 

 age- parallel to m and b, which arc usually to be observed, serve to 

 orient the crystals. It is also elongated in habit parallel to the 

 lirachyaxis ; again parallel to the macroaxis; but rarely are the 

 crystals elongated 

 parallel to the 

 vertical axis, as at 

 Metier, Hungary. 

 Parallel growths 

 are common when 

 tabular in habit; 

 they are joined by 

 the base, yielding 

 at times a cocks- 

 comb-like surface 

 or radiated, with 

 deep reentrant 

 angles separating 

 the individuals. 

 It also occurs in 

 beds, massive, 

 granular, radi- 

 ated, in banded 

 nodules, as well 

 as stalactitic. ' 



Barite is easily distinguished from other white minerals by its 

 weight, from which it takes its common miner's name of heavy 

 spar. The various shades, other than white, are due to impuri- 

 ih- It often contains calcium or strontium sulphates, with 

 which it is isomorphous. 



Barite is a secondary mineral associated with sedimentary rocks 

 and ore veins. In ore veins it is more often associated with lead 

 an< 1 /inc ores and with veins containing sulphides. In such veins it is 

 deposited through the interaction of percolating waters, carrying 

 barium in solution, either as the chloride or the bicarbonate, with 

 soluble sulphates, as gypsum, or with sulphates furnished by the 

 oxidation of sulphides, as pyrite. Beautiful crystals of barite are 

 2n 



FIG. 518. Barite and Dolomite from Cumberland, Eng- 

 land. 



