Vibrating tables replaced some of the round buddles to treat fine material, and an effort was made to recover some of the zinc blende in the ore, but this seems not to have been successful.
12.
When a fragment of radium salt is held near to a zinc blende screen, the positively charged particles given off by radium salts bombard it and render the surface of the screen full of rapidly changing brilliant points.
13.
This property accounts for the preferential formation of wurtzite rather than zinc blende structure, as well as the strong piezoelectricity of ZnO . Because of the polar Zn-O bonds, zinc and oxygen planes are electrically charged.
