TAKE A LOOK AT... (in Derbyshire)

This is a copy of an article published in The Peak Advertiser, the Peak District's local free newspaper, on 26th January 2004 (p16), reproduced by kind permission of its author, Julie Bunting.

TAKE A LOOK AT: MINERALS AND MARBLES

To the mineral collector the natural resources of the Peak District, where about a hundred different minerals have been recorded, are of considerable importance.

It became something of a vogue amongst nineteenth-century scholars to collect samples of minerals which were incidentally making a significant contribution to the Industrial Revolution.

About two hundred years ago large quantities of chert began to be mined around Bakewell. In great demand as a whitening agent in the manufacture of pottery, Bakewell chert was held in high regard by Josiah Wedgewood himself. Other silicon materials, notably amethyst and 'Derbyshire Diamonds', are attractive varieties popularly bought for display.

'Black Jack', otherwise known as blende, was a zinc mineral found at Eyam and Matlock: the word blende derives from a German word meaning to deceive, since the mineral resembles the lead ore, galena. Calamine was another useful zinc material, not only used in brass foundries but familiar as an ingredient in pink ointment and a soothing lotion.

Of the iron minerals, a variety of haematite known as 'raddle' occurs at Youlgreave, and limonite at Eyam and Winster. Ochre of the former was used as red pigment and of the latter as yellow. Similarly a black pigment for paint was obtained from manganese, known as black wad and found at Hopton and Elton.

GANGUE MINERALS

‘White lead’ from the Peak was also used in paint production, as was barytes or cauk, once ground in mills at Stoney Middleton, Ashford and Bonsall Dale. Several other industries utilise barytes, nowadays used too in oil-drilling and in making barium meals in connection with X-rays.

A unique decorative variety of barytes - Derbyshire Onyx or Oakstone - is found only near Arbor Low. Brown in colour, with fine pale banding, this rare mineral when polished closely resembles well-buffed oak.

Barytes is one of the gangue, or secondary, minerals associated with lead. Another is calcite, known as Iceland Spar and found at Castleton, Eyam and Matlock. Calcite now goes in the white paint used for road markings. Fluorspar was also discarded by the old miners as waste, but this came to have a vital role as a flux in steel-making and is now obtained by opencast mining.

The decorative Blue John is a unique type of fluorspar found in fourteen different varieties at Castleton. Although Castleton jewellery makers concentrate on Blue John, iron pyrites - familiar as tiny steel-grey crystals of marcasite - occurs around Mam Tor and Windy Knoll.

COPPER MINES

At the beginning of the seventeenth century copper was discovered at Ecton in the south-western Peak District, but it was the middle of the following century before it was successfully and profitably exploited by the Duke of Devonshire, who held mining rights. Smaller copper mines in the locality were worked at Onecote, Upper Elkstone and Waterfall. The mines all fell into disuse about a hundred years ago.

Two familiar copper minerals are the glittering copper pyrites, commonly called 'fool's gold', and malachite, which polishes to a distinctive bright green and is popular for jewellery and ornamental work.

Relics of Ecton's mining era can be seen in two copper-clad spires, one on a local house and the other, more conventionally, on Sheen church.

The font and reredos in this church incorporate local marbles, including the famous 'Duke's Red', found only in one lead mine at Alport. Due to its scarcity the stone was used sparingly but pieces can also be seen in the pulpit at Great Longstone church and both font and pulpit at Edensor.

'Duke's Red', like all the Peak's ornamental marbles, is actually an impure variety of limestone. The more abundant Ashford marble is a fine-grained limestone which takes on a jet black gloss when polished. Already quarried for interior features such as chimney pieces, it lent itself to a new industry which thrived throughout the reign of Queen Victoria, when Ashford Marble meant beautiful inlay work.

The fresh, glowing colours utilised local minerals and other marbles of all shades; Rosewood for reddish-brown, barytes in blue, rose-pink and yellow, and several shades of bird's eye marble - so called for its small white rings which are cross-sections of stalk-like fossils. A fine Ashford Marble specimen table is displayed in the village church.

One particular ‘bird's eye’ marble which continues to be used for interior building work is quarried at Hopton. Decorative Hopton limestone has been used in Westminster Palace, the Bank of England, Liverpool Cathedral, the Barbican Centre and closer to home in the Derbyshire County Council offices at Matlock.

© Julie Bunting
From "The Peak Advertiser", 26th January 2004.

Articles by Julie Bunting are reproduced with her kind permission.

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