History of Northwich February 2004 a £28 million programme to stabilise the abandoned salt mines underneath Northwich was begun. The work was funded by the English Partnerships through its Land Stabilisation Programme, introduced to resolve issues associated with unstable mines around England. The four mines identified for work were Baron's Quay, Witton Bank, Neumann's and Penny's Lane. These mines were chosen because their subsidence was causing problems for the town centre. When they were abandoned the mines were left with supporting salt pillars. Modern salt mining leaves around 30% of the salt to form the pillars but, because of the wild-brine pumping, the
Blue John (mineral) Blue John (mineral) Blue John (also known as Derbyshire Spar) is a semi-precious mineral, a form of fluorite with bands of a purple-blue or yellowish colour. In the UK it is found only at Blue John Cavern and Treak Cliff Cavern at Castleton in Derbyshire. During the 19th century, it was mined for its ornamental value, and mining continues on a small scale. Deposits of fluorite have been recently found in China with colouring and banding similar to the classic Blue John stone. The most common explanation for the name is that it derives from the French "bleu-jaune", meaning 'blue-yellow'.