Tourmaline is the most colourful of all gemstones. It occurs in all colours, but pink, red, green, blue and multicoylored are its most well-known gem colours. Tourmaline is a birthstone for October and the gem of the eighth anniversary. Tourmaline gemstones are semi-precious natural stones that are compounded with various elements like, aluminium, iron, magnesium, sodium, lithium, or potassium. Tourmaline gemstones come in a variety of colors. Some of the fairly common colours available are, green, pure blue, red, orange, yellow, purple, and pink. Raspberry-red rubellites and emerald-green chrome are among the most expensive and rare stones amongst all other tourmaline gemstones. Tourmalines are heat resistant (not highly though) and offer a good hardness that makes it ideal to wear them regularly. Rings made of tourmaline are available in pink tourmaline and green tourmaline, often accompanied in settings which incorporate diamonds or diamond chips to complement the use of tourmaline as the main gemstone in the ring. When used in the company of other gemstones, it becomes a chameleon of color, changing its look depending upon how the existing light hits the stone in the company of other gemstones in the same setting. Depending from which angle you view the gemstone the color may vary or the shade become more or less intense.