Question: what is pencil led made of

Reka Nagy answered on 17 Nov 2016:

Graphite, which is carbon that has a specific crystal structure. It may surprise you, but diamonds are also made of carbon – so technically you could convert your pencil lead into a diamond if you had access to pressures of about a million times higher than the pressure we experience at the surface of Earth, and temperatures above 2000 degrees Celsius!