Hemimorphite carbonate

This metal Stromeyer named cadmium, since cadmia is an old name for calamine or zinc carbonate, derived from the Lat. calamus reed, in allusion to its slender stalactitic forms. To avoid confusion it should be mentioned that American mineralogists know natural zinc carbonate under the name of smithsonite, after Smithson, who founded the Smithsonian Institute at Washington, and who analysed the mineral in 1803. Unfortunately, the Americans use the term calamine to designate our hemimorphite, ZnjSiCVHjO, or more probably Zn(0H)2"Zn,Sia07.Ha0, since one half of the... 

The main mineral from which zinc is extracted is the sulfide ZnS (sphalerite), although in some deposits the carbonate ZnC03 (smithsonite) and the silicate Zn4(OH)2Si20rH20 (calamine or hemimorphite) may also be abundant. 

The carbonate will react with hydrochloric acid, fizz and eventually dissolve if enough acid is added, whereas the sihcate (hemimorphite contains the sorosil-icate ion, Si207 ) will not readily react with acid. 

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