Minerals
Minerals are natural inorganic (non-living) substances that have the same chemical makeup and crystal shape.
A mineral's color depends on what's mixed in with it. Some minerals have metal with a metalic luster (how it reflects light) mixed in with them that causes them to shine.
Minerals that don't contain metals look dull. Some minerals you are very familiar with, and some you may never have heard of.
Here are some examples of things that are known as minerals.