A mineral is a naturally occurring, inorganic solid that has a defined chemical composition and crystalline structure. (However, rarely do introductory mineral samples show a good crystal form.) There are almost 4,000 identified minerals. They are categorized based on their chemical formula. Many minerals can be cut and faceted to create gemstones.
A rock is a solid mass made up of different minerals. But most rocks you see are composed of only a handful off minerals that are known as the rock forming minerals. These rock forming minerals include: quartz, feldspar, olivine, muscovite, biotite, pyroxene, amphibole, calcite, halite, and hematite.
Minerals have characteristic physical properties that can be easily measured. At the link below you will find a chart that lists the physical properties of some common minerals, and a table that provides the means for determining the physical property of a mineral sample. If you have lab equipment and some mineral samples at home, you can test your own.