Solid stuff
It takes a lot of things to make cookies—flour, milk, eggs, butter,
sugar. But when the cookies are baked, you can’t see that there are a
lot of things in them. Everything is all mixed together.
A rock is like a cooky. Mixed into most rocks are things that you can’t
see. Rocks are mixtures of materials called minerals.
Minerals are the solid stuff that the earth is made of. There are about
two thousand different kinds of minerals. Some are shiny, some are
sparkly, some are dull. Some are hard enough to scratch glass. Others
are so soft you can scratch them with your fingernail. There are
minerals that look like chunks of ice, minerals that look like clusters
of metal cubes, and minerals that look like bunches of fuzzy string or
shiny hair.
Minerals are scattered throughout the earth’s rocky crust. Many of them
are mixed together, but many are by themselves, in huge chunks, little
lumps, and broad patches between layers of rock.
minerals
Minerals are the solid material of which the earth is made. There are
about two thousand different kinds of minerals. Shown here (clockwise,
from the lower left) are: fluorite, azurite, malachite, selenite, and,
in the center, wulfenite.
