History of salt English places carry the suffix and are historically related to salt, including the four Cheshire 'witches' of Middlewich, Nantwich, Northwich and Leftwich (a small village south of Northwich), and Droitwich in Worcestershire. Middlewich, Nantwich, Northwich and Droitwich are known as the "Domesday Wiches" due to their mention in the Domesday Book, "an indication of the significance of the salt-working towns in the economy of the region, and indeed of the country". Salt was very important to Europe because it was hard to trade with Africa and they needed to produce it themselves. Monopolies over salt production and trade were essential
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'.