Rocks are found in large quantities in the earth's crust. The are formed by heat or pressure. Rocks go through a rock cycle just like the life cycle or the process of metamorphosis. Minerals are inorganic materials forming naturally in the earth. Minerals are usually categorized by thier property.
Minerals usually have crystal structure and a hardness by chemicals.
Prety interesting stuff. Now you now the differance between rocks and minerals. Now I'll tell how three different rocks or minerals are used. Fluorite is used for flouride in toothpaste. Silica is used for different computer chips, and quasi crystals are used for a variety of things like airplane parts to high quality resistors.