Calcite with Marcasite

specimen number:
1655503

location:
Magpie Mine, Sheldon, Derbyshire, England, UK

description:
Lustrous scalenohedral crystals of calcite dark in color due to inclusions of marcasite across the top of matrix. One crystal is cleaved as seen.

The Magpie Mine, situated near the village of Sheldon in the Peak District of Derbyshire, stands as one of the most iconic and best-preserved lead mines in England. Geologically, the deposit is a classic Mississippi Valley-Type (MVT) occurrence, where mineralizing fluids deposited galena within horizontal bedding planes and vertical fissures, known locally as "rakes," in the Carboniferous Limestone. These limestone host rocks are part of a massive carbonate platform that was subjected to tectonic faulting, allowing for the deposition of lead ore alongside gangue minerals like calcite, fluorite, and barite. Historically, the site has a long and turbulent record of operation, with the first documented mention of the mine dating back to 1740. It became infamous in the 1830s for a violent dispute with the neighboring Redsoil Mine, which resulted in the deaths of three miners. The mine saw several periods of modernization, including the construction of its distinctive Cornish engine house in 1869 to combat flooding. Although small-scale prospecting continued into the early 20th century, major operations ceased in 1883, with final exploratory attempts ending in 1958. Today, the site is a scheduled monument managed by the Peak District Mines Historical Society.

Questions about this specimen?
Send an email or call us: 314-341-1811.