Sparkling crystal druses of Quartz crystals had originally formed over cubic crystals of Fluorite, which have dissolved leaving the Quartz as impressions of the Fluorite. Latter crystals of metallic grey Galena have developed over the Quartz, with a single crystal of Tetrahedrite coated by Chalcopyrite, and a small closely associated area of Pyrite. A specimen from the well known Herodsfoot Mine.