A fairly nice example of open-vein type mineralization from this mine, a major copper producer in Cornwall and well known for it Bismuthinite specimens. This specimen in loaded with colorless, thin tabular and hexagonal Fluorapatite crystals to 1mm which are hard to see in the photos but are clearly seen with excellent definition under the scope. The Sphalerite is well crystallized also having a deep red to orange transparency. The old Barstow label mentions the association with "chalybite" a synonym of Siderite. In this case, Barstow, was mistaken, as this is Sphalerite, not chalybite. Also in the matrix is Pyrite. See the old Barstow label, under provenance. Barstow, who passed away in 1982 was one of the more famous mineral dealers from Cornwall, who actually worked at the South Crofty mine. More can be found on Barstow at the Min. Record label archive.