A slippery mineral
What is inside the pencil you use to write? It’s often called
“lead”—but it’s not really lead at all. It’s a mixture of clay and a
soft, black mineral called graphite (GRAF yt). Some graphite is found in
the earth, and some graphite is manufactured.
Graphite is not found in hard, many-sided crystals, as some other
minerals are. Instead, it is made up of flat layers that easily slide
over each other. This makes graphite soft and.slippery. When graphite is
used in pencils, it slides easily over the paper and leaves a black
mark.
Graphite is so slippery that it can sometimes be used in place of oil.
People use graphite to “oil” locks, clocks, and all sorts of small
machines. And in cold weather, when oil turns thick and hard, graphite
stays soft and slippery. In winter, and in cold places, it often works
better than oil.
The container that holds white-hot, melted steel is made of a material
that contains graphite.
graphite in pencil lead
Graphite can be used in other special ways. It does not melt easily, so
it is often used to make pots for melting- metals. It does not dissolve
easily, so it is often used in making tanks that hold strong chemicals.
And, even though a slippery, soft piece of graphite and a hard,
sparkling diamond don’t look much alike, they are both made of the same
kind of material. So graphite is used to make artificial diamonds for
cutting and grinding. The diamonds made from graphite work as well as
real diamonds do.
a steel foundry
