MERCURY ORES. 71 



Structure sectile. 



H. 2 to 2-5 ; S.G. 6 to 8. 



Contains 86 per cent, of mercury, the rest sulphur. 



Is volatile before the B.F. Soluble in aqua regia (4 

 hydrochloric acid and 1 nitric acid), but not in either 

 hydrochloric or nitric acid. A piece of clean copper placed 

 in the solution will be coated with a film of mercury. 



If the powdered ore be placed together with quicklime in 

 an iron pan and gently heated, a globule of mercury will be 

 found at the bottom of the pan. 



If the powdered ore be placed in a glass vessel capable 

 of standing heat, such as a thin oil flask, and exposed to a 

 strong flame, the mercury will form a sublimate on the 

 upper and cool part of the vessel. 



If heated in a tube closed at one end, globules of mer- 

 cury condense on the cool portion. Near the test piece a 

 black (red on being rubbed) sublimate is formed. 



By placing powdered ore in the mouth of a tobacco-pipe, 

 closing the mouth with clay, and exposing the bowl to a 

 fair heat, the mercury may be collected on a cool surface, 

 held so that the fumes given off may be condensed. 



A gold coin or a piece of clean copper placed in the fumes 

 will soon have a deposit of mercury on its surface. 



Chloride of Mercury (horn quicksilver). 



Is crystalline and granular, of a dirty white or ash grey 

 colour, and a yellowish streak. Frequently associated with 

 cinnabar. 



H. 1 to 2 ; S.G. 6-48. 



Selinide of Mercury. 



Of a steel or lead grey colour and metallic lustre ; occurs 

 in Mexico. 



The following are some of the places where cinnabar is 

 found and its mode of occurrence : 



California As deposits in cretaceous rocks, &c. 

 Idria in Illyria Disseminated through bituminous schist, 

 limestone, or grit. 



Spain In veins traversing a micaceous schist. 



