From the ArcaMax Publishing, Trivia Newsletter:
http://www.arcamax.com/news/trivia/s-342347-149666
Some time prior to 1665, an enormous deposit of graphite was discovered at the site of Seathwaite Fell near Borrowdale, Cumbria, England. The locals found that it was very useful for marking sheep. This particular deposit of graphite was extremely pure and solid, and it could easily be sawn into sticks. This was and remains the only large scale deposit of graphite ever found in this solid form.
This news arrived on: 05/02/2008