What a Mineral is
A mineral is a chemical element or compound that is naturally occuring and has a crystal structure. A rock is a natural material that is made up of one or more minerals. A mineral is made of one or more elements. There are steps to identify a mineral: hardness, lustre, streak, cleavage, and fracture.
Hardness
Hardness is judged by how easily a mineral scratched. There is a scale that is used to tell you how easily it is scratched called Mohs Hardness Scale and there are 6 levels of hardness. For example, a soapstone is hardness 1, because you can easily scratch it with your finger nail and see the mark clearly. Glass is hardness 5 because you can't scratch it with your finger nail and see a mark.
Lustre
Think of Lustre as another word for texture. So if I had a mineral and I asked what lustre it is, what i'm really asking is, "How shiny is it?" Waxy, pearly, glassy.
Streak
A streak is a mark on your mineral that can be tested by striking a mineral on a piece of unglazed tile. If it leaves a mark on the unglazed tile it's called a streak. It can help you identify what mineral it is by looking at the colour of the streak.
Cleavage and Fracture
Cleavage and fracture refers to the way a mineral breaks. If a mineral breaks smooth and thin than it's a cleavage mineral. If your mineral breaks in jagged edges then it is a fracture mineral.
Colour
Minerals have many different colours so we can't identify minerals on colour alone.
Crystal Structure
Crystals have stright edges, flat sides, and regular angles.