Buy a packet of refills for a mechanical pencil and the label will probably call them leads. We’ve used that name for centuries, ever since graphite was mistaken for a type of lead.
It was an understandable mistake. Graphite is grey and can have a metallic shine. People called it “black lead”, or “plumbago”, from the Latin word for lead, plumbum. They could write with it, but they didn’t yet know what it was made of.
Graphite from the Lake District
In the 16th century, graphite mined at Borrowdale was being used to make pencils. The material could be cut into thin sticks, which saved pencil makers having to grind it down and mould it. Those sticks were fragile. Wrapping them in string helped, and wooden holders gave them more protection. The wood also made the graphite easier to hold while writing.
You will often see 1564 given as the year of the discovery. There are mining records from 1540-41, though, so that date doesn’t tell the whole story.
The name stayed
Carl Wilhelm Scheele identified graphite as carbon in 1779. Another ten years passed before Abraham Gottlob Werner named it graphite, using the Greek word graphein, meaning “to write”.
By this point, “lead” had been used for the material for more than two hundred years. Knowing itscomposition didn’t change what people asked for when they wanted a pencil.
Pencil making changed too. In 1795, Nicolas-Jacques Conté developed a process using powdered graphite mixed with clay, then fired in a kiln. The amount of clay affected the hardness, allowing manufacturers to make different grades.
An ordinary wooden pencil still uses that mixture. More clay produces a harder core and a lighter mark on the paper.
So where does graphite come from today?
China supplies most of the world’s mined graphite, with other producers including Madagascar, Mozambique, Brazil and India.
Borrowdale’s mines closed in the 19th century.
A large portion of the graphite used today is not mined at all; it is synthetic. This synthetic graphite is used in batteries and steel production, among other industries.
For pencils, manufacturers mix graphite powder with clay, although where they buy the graphite depends on the manufacturer.
Sources / Further Reading
https://www.bl.uk/stories/blogs/posts/the-history-of-the-pencil
https://historicengland.org.uk/listing/the-list/list-entry/1019941
https://www.britannica.com/biography/Carl-Wilhelm-Scheele
https://www.writeherekitenow.co.uk/mechanical-pencils.html
