Sand is actually a mixture of small particles of many different types of rocks and minerals.
You can find lots of sand on beaches and in deserts.
If you mix sand with some water, you can make sandcastles!
Sand is also used to make concrete.
There are actually many types and colours of sand. Some beaches have green or even black sand.
Some animals like the crab, like to live in the sand, so you have to be careful when you go digging at the beach.