Tourmaline is a silicate mineral that comes in a wide range of colors, often seen as a gemstone. Its name is derived from the Sinhalese word turmali, meaning "mixed color" or "stone of many colors," reflecting its ability to occur in virtually every color of the rainbow. The mineral is composed of complex boron silicates and can form in several different crystalline structures.

Tourmaline's most notable feature is its striking color diversity. It can range from shades of red, pink, and green, to blue, yellow, brown, and even black. Some of the most popular varieties include Paraiba Tourmaline (vivid neon blue or green), Rubellite (red to pink), and Verdelite (green). Tourmaline can also exhibit a unique color zoning or multi-colored variations, where different parts of the same crystal display different colors.

One fascinating property of tourmaline is its ability to exhibit pleochroism, meaning it can show different colors when viewed from different angles. Additionally, tourmaline can be pyroelectric and piezoelectric, meaning it can generate an electrical charge when heated or subjected to pressure.

Tourmaline is widely used in jewelry due to its hardness (7 to 7.5 on the Mohs scale) and vibrant colors. It is also believed to have various metaphysical properties, including enhancing emotional healing and promoting a sense of balance.