Super lustrous black Sphalerite crystals on contrasting crystals of Siderite. This piece is from the noted Cornish collection of Lewis Barton (his label is included), and is a superb Sphalerite from anyplace in Cornwall and likely the best known from the Ale and Cakes Mine (which is a great name for a mine)! Despite a few edge nicks and contacts the overall quality and condition is really fine. A choice addition for any good Cornish or UK suite.