This sphalerite is from the Elmwood Mine in Carthage, Smith County, Tennessee, Ba-F-Pb-Zn District, Tennessee, USA. 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. It is a sulfide containing the elements Zn and S. This is a large complex-tetrahedral crystal. It is good on all sides. It has a mirror bright luster and when brightly back lighted translucent ruby highlights can be seen. It measures 1 3/16 x 1 1/8 x 5/8 inches or 30 x 28 x 16 mm.