Where does pencil lead come from? That’s one of those questions you start pondering in the middle of a too-warm afternoon when you’re sitting at a desk with a pencil in your hand, working, when you’d rather be anywhere else but there.
So, for the next time your mind gets to wandering, here’s the answer:
Pencil lead does not come from lead. In fact, even though it’s greasy and black and soft like lead, it is actually a carbon material called graphite. Graphite is mined as flakes or lumps and ground together with clay, then baked into the little sticks you see encased in wood or inside mechanical pencils.
(Check out this video from pencil maker Faber-Castell showing how pencil lead is produced. Pretty cool.)
Graphite was first discovered in the late 1500s in Borrowdale, in northern England’s Lake District. Supposedly, a storm blew over some trees and exposed a dull black material that the locals began using to mark their sheep. Word spread of the find, and eventually people discovered they could cut the material and form it into sticks with which to write.
The area became a center for pencil making and is now the site of the Cumberland Pencil Museum.
Because it looked like lead, the pencil material was known as plumbago, or lead ore. But, in 1779, chemist Carl Scheele made the discovery that it was a form of carbon and unrelated to lead. The word graphite came from the Greek verb graphein, which means, “to write.” Still, people continued to refer to it as lead.
At first, the Borrowdale deposit was the main source of pencil lead throughout Europe. However, there were deposits of graphite in less solid forms in many other parts of the world. In 1795, a Frenchman named Nicholas Jacques Conté figured out a way to mix clay with graphite powder and bake it in kilns to form pencil lead.
That discovery eventually led to the demise of the pencil factories around Borrowdale because graphite could be so easily obtained elsewhere. Now, according to a report from the U.S. Geological Survey, the largest deposits of graphite are found in China, Europe, The U.S. and Mexico. China is one of the main exporters of pencil leads.
As a matter of fact, Discover Magazine recently reported that:
More than half of all pencils come from China. In 2004, factories there turned out 10 billion pencils, enough to circle the earth more than 40 times.
In a bit of irony, Canadian health officials recalled some Chinese pencils a couple of years ago because the pencil coatings were contaminated with….yep, lead.
If you want to know more about pencil leads, especially the sizes and hardness levels used in mechanical pencils, go over to Dave’s Mechanical Pencils and read his blog post.