This is a most unusual fluorite specimen, from the older fluorspar district of the region in Alston Moor. A green core gives way to color-zoned lavender and purple hues in this glassy and gemmy, equant, penetration twin of fluorite. Two faces have been preferentially coated with a druse of siderite. When backlit with a quartz halogen lamp the specimen explodes with neon, rich fluorite colors. Under the ultraviolet light or in sunlight the color is even more a deep rich grape-juice purple color. An old specimen probably from prior to the 1870s, this was long in the Ralph Sutcliffe collection - sold in 1991 to the Greenbanks.