a large specimen of dog tooth calcite ex Middleton Mine, Wirksworth. Collected during an official visit when the mine was open – it closed around 2005 – so no more specimens like this – officially anyway.
|Origin||Middleton Mine, Wirksworth|
Middleton mine was reputed to have over 20 miles of workings covering an area of 1400 metres west to east and 800 m north to south over 3 levels. Originally an open surface quarry, deep excavation work later began in 1959. The decision to burrow can be attributed to the increasingly uneconomic method of stripping the overburden which not only increased the quarry depth and overall width of the area being mined, making it ever more difficult to transport material in and out of the site, but also destroyed much of the surrounding moorland. Work on the drift access began on the 4th February 1959 and, up to 2005 – the year the mine finally ceased operations, an estimated 16 million tonnes of high grade limestone had been extracted via the underground workings. Although out of date see more at Hopton Wood Stone website