Birthstone Month:
Tourmaline is one of the two gemstones associated with the month of October.

Zodiac:
Being one of the two accepted birthstones for the month of October, Tourmaline is one of the zodiac gemstones for Libra and Scorpio.

Chemical Symbol:
The general symbol for Tourmaline is (Na, Ca)(Li, Mg, Al)(Al, Fe, Mn)6(BO3)3(Si6O18)(OH)4

Chemical Make-up:
Tourmaline is made up of the complex Aluminum Borosilicate element, and depending upon the color of the gemstone, one or more of a number of metal ions, usually Iron, Magnesium and Lithium. Yellow Tourmaline owes its color to traces of Magnesium.

History & Lore:
The name Tourmaline is widely accepted as being derived from the Singhalese expression tura mali, which when translated means “stone of many or mixed colors”.

Tourmaline is often referred to as the rainbow gemstone, due to the huge amount of colors that it is available in. This was certainly believed by the ancient Egyptians who believed that when Tourmaline traveled from its home in the earth's core to the surface, it did so along a rainbow, which subsequently gifted the gemstone with all of the colors of the rainbow.

Tourmalines exhibit piezoelectricity and when these stones become warm they become electrically charged – positively at one end and negatively at the other, acting like a magnet and strong enough to attract small particles of dust or ash. It is for this reason that the Dutch of old used Tourmalines to clean their pipes!

Yellow Tourmalines are believed to activate the solar plexus chakra which can in turn enhance personal power and intellectual pursuits. In addition to this, Yellow Tourmalines are said to bring heightened intelligence, creativity, initiative, and spiritual awareness.

Availability:
Yellow Tourmaline gemstones are highly sought after by collectors and are rarely used in commercial jewelry, not only because they are currently being mined in but one location, but also because only 10 percent of these mined stones are suitable for jewelry purposes. In addition to this, Yellow Tourmaline rarely occur in large sizes. It is estimated that after being cut, over 95 percent of the stones will weigh less then one carat.

Sources:
Yellow Tourmalines are currently being mined in Malawi, a country located south of East Africa.

Evaluation:
Tourmaline (regardless of variety) is rated at 7 – 7.5 on the Moh's Scale of Hardness and as such is suitable for all jewelry uses and is considered durable enough to be worn everyday.

Found in an amazing variety, the sheer number of available Tourmaline colors is second to none and unmatched by any other gemstone. Tourmalines can be found in shades of blue, black, brown, colorless, green, orange, pink, red, yellow and other colors in varying shades and hues, varying from completely transparent to opaque. In addition to this there are also known occurrences of bi-color, tri-color, mulit-color and “Cat's Eye” Tourmalines, ensuring that the Tourmaline truly is a gemstone that is available in a color to suit all styles and tastes.

A Tourmaline gemstone viewed from different angles will result in differing color intensities being visible. The only one thing that you can be sure of is that the deepest coloration will always be shown along the stone's main axis. When selecting a Tourmaline, go with the color that you like but generally try to steer clear of any stone that is cut too dark.

Yellow was formerly the missing color that was needed to complete Tourmaline, the “Rainbow Gemstone”. Although yellow Tourmalines were being mined, most displayed a brownish tinge that greatly decreased their overall value and desirability. Then in the autumn of 2000, rumors surfaced that beautiful yellow Tourmalines had been discovered in Malawi, a country located south of East Africa. The rumors were in fact true, and bright yellow colored Tourmalines soon became offered in the market.

Yellow Tourmalines offer a pleasant lemon yellow color with an occasional fine greenish hue. The Malawi deposits will also occasionally have a brown undertone but will most often be removed through both the heat-treatment process and by the cutter. Another unique and interesting characteristic about Yellow Tourmalines is their fine scent. This scent is of course not natural and can't be enjoyed by the wearer but instead by the cutter who fashions the stone. This is because when Tourmalines are mined they are often found embedded in black material which will need to be removed before the stone can be cut. An owner of one Malawi mine discovered that the black material can be removed quite effortlessly by boiling the stones with a little lemon juice. Because of this interesting experiment, cutters can enjoy the fresh scent of these stones well fashioning them.

Common Cuts:
Owing to the fact that Tourmaline crystals are long and narrow in shape Tourmaline gems are most commonly, although not exclusively cut into square or rectangular stepped shapes.

Routine Enhancements:
Yellow Tourmalines are occasionally heat-treated in order to remove unwanted brown undertones and to remove “silk” (a form of natural imperfection / inclusion). Some colored Tourmalines actually transform into other Tourmalines (most commonly the Achroite Tourmaline variety), during this heating process.

Care & Cleaning:
Use warm, soapy water and a soft brush to clean Tourmaline. Ultrasonic cleaners are generally safe. Never use chemicals such as hydrofluoric acid or ammonium fluoride to clean Tourmaline because it can erode the stone. Much like many gemstones, Tourmaline should be kept away from prolonged exposure to extremes of heat and light as this can cause permanent color change. Always keep your Yellow Tourmaline jewelry in a fabric-lined box, away from other jewelry, in order to avoid damage/scratching.