A cabinet specimen of calcite on mixed sulfides (marcasite or pyrite and perhaps sphalerite) from the classic mining district centered around Galena, in the far northwestern tip of Illinois.

There is damage to the calcite crystal, on the reverse and on the lower portion of the front. but unless you are looking closely, it is rather difficult to see, given that the crystal is not especially gemmy.

This mining area is part of the Upper Mississippi Valley District, the same district in which the Schullsburg, Wisconsin deposit is situated.  Both areas are now closed, but the mines around Galena were much earlier--operating from the early 1800's until the early 1900's, and producing about 80% of the nation's lead by the 1840's.  Small scale mining had been conduced by the French begining around the 1690's, and the location was also known to Native Americans for some time before their arrival.

Given that these area saw its peak almost 150 years ago, at a time when few specimens were saved, these specimens are exceedingly rare today.  It is admittedly not in perfect condition, but it is a very rare and old example of classic American meterial.