Museum-size cabinet specimen from the historic and now defunct Joplin Field, Tri-State District. Sharp sphalerite crystals reaching 6 cm show clear epitaxial growth with chalcopyrite. The matrix is richly coated with lustrous, iridescent brassy chalcopyrite pyramids perched on pastel-pink dolomite rhombs. A classic old-time combination, highly showy and representative of one of the most renowned American mining districts, ideal for advanced collectors and institutional collections.