QUARTZ epimorphs after FLUORITE with SPHALERITE

SPECIMEN DESCRIPTION

This is a classic British epimorph from the famous Nenthead mines in Alston Moor. Fluorite of many colours is common in many of the northern Pennine mines, but in Boundary Cross Vein in Rampgill mine distinctive epimorphs of hollow cubic Quartz casts after long gone Fluorite are a major feature. This delicate thin layer of Quartz casts after Fluorite cubes has a 'ring' to it, almost like ceramic. Often the internal cast is studded with glossy black Sphalerite crystals. On this piece the inside layer is coated with brown iron oxides upon which several small glossy Sphalerite crystals can be seen. The outer surfaces of the casts are quite coarsely crystallized with a layer of sugary Quartz crystals but still display the outline of the original aggregate of cubic Fluorite crystals which makes quite an artistic display. A North Pennines classic.