Masses of sulphuret of zinc, in the form of blende, were noticed at this locality.
Zinc is smelted in England, likewise from blende (sulphuret of zinc).
The ores are argentiferous galena, accompanied by considerable amounts of blende and pyrites, all oxidized near the surface.
It is said to require the reduction of about five thousand tons of the blende to produce one pound of radium.
The blende is first roasted in huge furnaces specially built for the purpose.
It probably is not rich enough for amalgamation, as it contains a superior bulk of iron pyrites, blende, lead and earthy matter.
Tetrahedrite, blende, diamond, boracite and pharmacosiderite are substances which crystallize in this class.
In the Missouri region, on the other hand, sphalerite and blende are the typical ores.
Hemimorphite occurs with other ores of zinc (calamine and blende), forming veins and beds in sedimentary limestones.
The gold is also often visible to the naked eye in all the associated minerals, and particularly in the mispickel and blende.