October has two colorful birthstones: Opal and Tourmaline.
Tourmaline is a boron silicate crystalline mineral, and can be compounded with several elements, including aluminum, iron, magnesium, sodium, lithium, or potassium. The Tourmaline mineral group is chemically one of the most complicated groups of silicate minerals. Tourmaline gemstones come in a wide variety of appealing colors including green, brown, black, blue, pink, yellow, red, purple, orange and grey and crystals can also be bi-colored or tri-colored.
Metaphysical properties of Tourmaline
It is thought that Tourmaline promotes inspiration and happiness. The gem may reduce fear and help the holder to build self-confidence. Tourmaline stones are used to balance the yin-yang energies, and crystals are physical bridges to the spiritual realms.
On the market
Nearly every color of tourmaline can be found in Brazil in the states of Minas Gerais and Bahia. A beautifully-colored new type of Tourmaline caused by the element copper was discovered in 1989 by Paraíban miners. This new stone became known as Paraiba tourmaline, is colored a brilliant blue and green and usually contains many inclusions. Most Paraiba actually comes from the neighboring state of Rio Grande do Norte in Brazil, but can be less intense in color.
Pink to red stones are often altered using heat treatment to improve their color. Pale pink hues in manganese-containing stones can be greatly deepened using irradiation with gamma-rays or electron beams. Irradiation is nearly impossible to detect in Tourmaline but does not usually affect value. Rubellite and Paraiba stones are often heavily included, so they are sometimes enhanced for clarity, but Tourmaline treated using this method are typically worth much less than untreated stones.
Tourmaline Gemstones and Jewelry
In general, Tourmaline is stable to light and chemicals, but heat may damage a gemstone. Stones treated by irradiation may fade with exposure to heat or bright light. Clean unset gemstones and finished Tourmaline jewelry in lukewarm soapy water using a soft cloth or brush.