These sphalerite crystals are from the Elmwood Mine in Carthage, Smith County, Tennessee, Ba-F-Pb-Zn District, 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. This is a rosette-like cluster of complex crystals with minor dolomite crystals attached. This piece is a large thumbnail that measures approximately 1 1/16 x 1 x 7/8 inches or 26 x 25 x 22 mm.