Spinel is a mineral that comes in a variety of colors, including red, blue, and black. It is often found in metamorphic rocks and is known for its hardness, ranking 7.5 to 8 on the Mohs scale. Spinel is commonly used as a gemstone in jewelry due to its brilliance and durability. In addition to its aesthetic appeal, spinel is also significant in the field of geology. It can form in different environments, including volcanic and sedimentary settings. Some spinel varieties are even used as a source of magnesium and aluminum, making them valuable in industrial applications.