Galena

Unknown Owner

Very nice grouping of large crystals for this locality, semi lustrous cubic crystals of galena in a cluster without matrix. In good condition. The size provided is measured along an edge, if measured on a diagonal this is slightly over 10.0 cm across.The Smallcleugh Mine is located near Nenthead in the Alston Moor district of Cumbria, within the Northern Pennine Orefield of England. Geologically, it is a classic Mississippi Valley-Type (MVT) deposit hosted within Carboniferous-aged limestone and sandstone, specifically focusing on the mineralized "flats" where hydrothermal fluids replaced the Great Limestone. These fluids, circulating approximately 290 million years ago, deposited rich concentrations of galena and sphalerite along with gangue minerals like fluorite, barite, and quartz. Historically, the mine was a major producer of lead during the 18th and 19th centuries under the management of the London Lead Company, which implemented advanced hydraulic engineering and drainage systems like the Nent Force Level. The mine is world-famous among mineralogists for its "Ballroom," a massive underground cavern created by the extraction of ore, and for producing exceptional "cockscomb" baryte and "classic" Alston Moor fluorite. Specimens from Smallcleugh are often characterized by their sharp, interpenetrating twin crystals of fluorite, which frequently exhibit a beautiful amber to honey-yellow color, sometimes coated with sparkling "sugar" quartz or associated with metallic galena. Although commercial mining ended in the early 20th century, the mine remains a legendary site for underground exploration and is a primary locality for studying the complex replacement textures of the Northern Pennine mineral suite.