These sphalerite crystals on are from the Elmwood Mine in Carthage, Smith County, Tennessee, Ba-F-Pb-Zn District, Tennessee, US. This mine contains three shafts called the Elmwood, Cumberland, and Gordonsville. It has an entry slope called the Stonewall. They contain eleven different minerals including sphalerite which is the main ore mineral. Sphalerite is a sulfide and it contains the elements Zn and S. This is a plate-like formation of complex sphalerites with a minor calcite crystals attached.This piece measures 3 5/8 x 2 5/8 x 1 inches or 92 x 66 x 26 mm.