To determine a mineral's hardness, rub the mineral against another known mineral or object to see if it will become scratched. The following chart indicates how you might test a mineral for hardness using a combination of Friedrich Moh's and field hardness scales. 1 represents the softest mineral while 10 is used for the hardest mineral. A mineral is able to scratch a mineral with a lower number and can, therefore be scratched by a mineral with a higher number.
Specific gravity is the ratio of the density of a mineral compared to the density of water.
It is a more specific way to compare the densities of minerals. A number of different minerals have the same color. A mineral may come in a variety of colors or may even change color due to the environment. Examples of luster include - metallic, nonmetallic, brilliant, glassy, greasy, pearly, or silky. A mineral's streak color may differ from the color of the mineral itself.