Varieties: Quartz comes in many varieties, including clear quartz (colorless), amethyst (purple), citrine (yellow), rose quartz (pink), and smoky quartz (brown to gray). Each variety can have distinct properties and uses.

Formation: Quartz crystals can form in a variety of environments, including igneous, metamorphic, and sedimentary rocks. They often form in hydrothermal veins or pockets within rocks.

Properties: Quartz crystals exhibit piezoelectric and pyroelectric properties, meaning they can generate an electric charge under mechanical pressure or heat. This makes them valuable in electronics, such as quartz watches.

Uses: Quartz crystals have many practical applications beyond jewelry. They are used in electronics for oscillators, resonators, and filters. They are also used in optics, lasers, and even in some medical devices.