112 BULLETIN 131, UNITED STATES NATIONAL MUSEUM 



of the most productive zinc mines in the world, has a large vein 

 deposit of high-grade sphalerite containing a very subordinate 

 amount of galena. When visited by the writer in 1914 this mine 

 had exposed on one level a body of nearly pure sphalerite ore 400 

 meters (1,200 feet) in length and in places reaching a width of 5 

 meters (18 feet). Qther zinc mines in this section are the Clarke 

 (Sunset), and Rex (16 to 1). 



The mines near Wardner contain very little sphalerite, the Bunker 

 Hill making no zinc product while the Caledonia, Sierra Nevada, 

 Ontario, and other veins of the group contain almost no sphalerite. 



The Pine Creek district contains a large number of sphalerite 

 bearing veins from some of which considerable zinc has been pro- 

 duced. Many of these carry, in addition to the galena and sphaler- 

 ite, much pyrite, pyrrhotite, and some chalcopyrite. Some of these 

 ores are characterized by a contemporaneous intergrowth of sphalerite 

 and galena which is so exceedingly fine that neither mineral can be 

 detected with a lens. 



Some veins of the North Side district, on tributaries of Prichard 

 Creek, contain considerable amounts of sphalerite, as, for example 

 the Granite-Allie, Cedar Creek, Monarch, Paragon, Terrible Edith, 

 and others. 



In general the sphalerite of the Coeur d'Alene district is poor in 

 silver and characterizes silver-poor ores. 



WASHINGTON AND ADAMS COUNTIES 



A specimen of typical ore from the Azurite mine shows almost 

 white (cleiophane) sphalerite in massive form with galena and 

 tetrahedrite in white quartz. 



METACINNABARITE (59) 

 Mercuric sulphide, HgS. Isometric. 



Metacinnabarite has been identified only in one locality in Idaho 

 and that is in Blaine County. 



BLAINE COUNTY 



A specimen of cinnabar collected by C. P. Ross from the Dockwell 

 tunnel near the head of Deer Creek in the Hailey district consists of 

 drusy crusts of minute indistinct cinnabar crystals lining open spaces. 

 Resting on the cinnabar are a few perfectly spherical smooth and 

 lustrous globules of black color 1 millimeter or less in diameter- 

 These, when crushed and examined under the microscope, are per- 

 fectly opaque and black with a metallic luster. Heated over a flame 

 they volatilize leaving a little white gangue surrounded by a yellow 

 halo on a slide glass. The mineral is doubtless metacinnabarite. 



