Tourmaline is a complex crystalline silicate containing aluminum, boron and other elements, used in electronic instrumentation and, especially in its green, clear, and blue varieties, as a gemstone. Its name has been derived from the Singhalese expression "tura mali" meaning stone of mixed colours.
The name refers to the unique spectrum of colors displayed by this gemstone. Tourmalines are red and green, range from blue to yellow. There are Tourmalines, which change the color from daylight to artificial light and others display chattoyance
