Fluorite with Siderite

Unknown Owner

Lustrous gemmy cubic crystals of fluorite measuring to 3.5 cm in size covering the top of matrix. Brown crystals of siderite and golden chalcopyrite are scattered throughout. Some damage present, still in good condition considering the age in size of this piece. Brightly fluorescent. The West Pasture Mine, located near Stanhope in Weardale, County Durham, England, was a notable producer within the Northern Pennine Orefield. Geologically, the mine exploited mineralized veins hosted in Carboniferous limestones and sandstones, where hydrothermal fluids deposited rich layers of galena and fluorite. The site is particularly famous among mineralogists for its exceptional green fluorite crystals, which are often transparent and exhibit a distinct twinning habit. Historically, mining and quarrying in the West Pasture area began in the 19th century as part of the broader regional effort to extract lead ore, though it later became an important source of fluorspar for the steel and chemical industries. The most significant periods of modern operation occurred during the mid-20th century, specifically between the 1940s and the early 1960s, before declining economic conditions led to its closure. While the physical infrastructure has largely vanished, the mine remains a significant historical reference point for collectors of English fluorite.