Mining Graphite

From 'Gangue Minerals and Pigment Earths' by Michael Shaw

Graphite is an allotrope of carbon, a black semi metal also known as plumbago or black-lead. The mineral was known of by the monks of Furness Abbey who are reported to have used it to mark their sheep (Lax & Maxwell 1998) and to rule guide lines in documents[4]. By the late 16th century it was certainly in use as a drawing material and probably for rust proofing iron (grate polish etc) (Camden 1610). The mine passed through many hands including in the early 17th century the Hechsetter brothers, as a private venture rather than as part of their Mines Royal activity. The most significant uses during the 18th century were for moulds for cannon balls and other iron munitions, crucibles and lubrication for ship’s rigging. These uses gave the material immense value, £3,500 a ton being noted c.1800 [4]. The material led to the development of the Keswick pencil industry in the late 18th century with locally mined graphite being used for the best quality pencils until stocks were exhausted before the First World war, mining having ceased c.1891. Graphite occurs as pipes, lumps, nodules, sops or bellies up to 1m by 3m, often following quartz strings.

         [4] http://www.conistonlocal.co.uk/striking-black-gold-in-the-lakeland-fell-tops-1.692082?referrerPath=home

Seathwaite graphite was 98 per cent pure carbon and had a melting point of 3,927C. This made it wonderful for blacking fire grates but even better for greasing the blocks and pulleys on Royal Navy ships and for making rifles and canons fire faster and more accurately.

So important was this national resource that an Act of Parliament was introduced in 1752 to prevent the stealing of graphite. Among the punishments was transportation.

By 1800 graphite was worth £3,500 a ton and a time when lead was worth just £15 a ton and the average miner was earning a £1 a week.

Armed guards patrolled the mine site and miners were searched at the end of work to try and prevent pilfering – with limited success.

The pieces missed by the guards were sold at local pubs and possibly gave rise to the expression black market and to a wad of money.