Graphite is a dark shiny black rock.
One interesting thing about graphite is that if you look at what it's made of, it's the exact same as a diamond.
Both are made from the chemical element called Carbon.
The difference is that the diamond was squished and heated up for a long long time.

(from: wikipedia - graphite)
Graphite also comes off if you rub the rock on something.
The dark part of the pencils that you write with is graphite.

(from: wikipedia - graphite)
Kid Facts - Blast from the past: Molecules