USEFUL METM..< 127 



Native mercury occurs in small globules scattered through 

 cinnabar and metacinnabarite as a product of reduction ly 

 organic matter. Bituminous substances, as idrialite and napa- 

 lite, are commonly associated with cinnabar. A. Liversidge re- 

 ports native mercury from the hot-spring deposits of New Zealand. 

 According to J. D. Dana, native mercury is found in Venetian 

 Lombardy in the marl beds regarded as a part of the nummulitic 

 beds of Eocene age. It has also been observed in the drift in 

 Transylvania. 



Cinnabar appears to have more than one method of forma- 

 tion. According to F. W. Clarke, mercury and sulphur, under 

 the influence of heat, unite directly, and the product upon sub- 

 liming is of scarlet hue. The black sulphide when acted upon 

 by solutions of alkaline sulphides can be converted into the red 

 form. The solubility of mercuric sulphide manifestly depends 

 upon conditions of temperature, pressure, concentration, and 

 the nature of the solution employed. G. F. Becker has found 

 that mercuric sulphide is precipitated again from solution in 

 alkaline sulphides upon dilution. Relief of pressure may in 

 some cases be the equivalent of dilution as a precipitant. A. 

 Liversidge has reported mercuric sulphide in the hot-spring 

 deposits of New Zealand. Cinnabar has also been observed in 

 the process of deposition by solfataric action at Sulphur Bank, 

 California and Steamboat Springs, Nevada. The black sulphide 

 is precipitated whenever H 2 S meets neutral or slightly acid 

 solutions of mercury salts in the mercuric state. It does not 

 follow that the mercurial solutions have been the same in all 

 localities. They must have varied both in their chemical com- 

 position and in the physical condition under which they came 

 to the surface. Their properties would be modified by the dif- 

 ferences in the rocks traversed by the solutions themselves. 



Calomel is a product of secondary origin in Idria in Carniola, 

 Almaden in Spain, Horzowitz in Bohemia, Belgrade in Servia. 

 Amalgam is often formed where veins of mercury and silver 

 intersect each other. 



Character of the Ore Bodies. The ore bodies bearing mercury 

 in some cases fill fissures, fractures, or cavities in sedimentary rocks. 

 In some instances cinnabar forms impregnation deposits in sand- 

 stones or limestones. These terranes are usually in the vicinity 

 of igneous rocks from which the mercurial ores were originally 

 derived. Deep-seated granites may have been the principal 



