One of the October Birthstones is Tourmaline

Cut and Clarity for the October birthstone

Tourmaline can be found in rather large deposits with robust crystal sizes as well as flawless clarity. It is not uncommon, however, to find inclusions in Tourmaline, especially captured liquid since Tourmaline often grows in moisture-rich environments. If the gem-quality Tourmaline displays pleochroism, gem-cutters must be careful to take this into consideration to emphasize the differing colors as much as possible. Low-quality Tourmaline is often turned into cabochons. Some Tourmaline displays a chatoyant cat’s eye effect thanks to parallel inclusions. Gem-cutters are able to capitalize on this effect when cutting into cabochon shapes. Tourmaline has been used throughout history for carving decorative figures since it does not easily crack during shaping. Higher quality Tourmaline is cut into a variety of classical shapes for use in jewelry applications. Typically, gem-cutters favor elongated shapes such as rectangles. It is not uncommon however for commissioned pieces to be cut in unique and Art Deco shapes for visual intrigue.

The value of Tourmaline

Just as varied as the colors of Tourmaline, so is the value. Common colors, even in larger sizes, are worth less than rare colors. The rarest color, and therefore most highly valued, is pink. The pink variety of Tourmaline is actually considered to be rarer than Rubies. If the quality is high enough to be considered facet-quality rough, prices sharply rise.

Is Tourmaline ever treated?

It is not uncommon to find Tourmaline with minute cracks, and therefore has been known to be treated with colorless resins. The coating of resin improves overall appearance as well as the durability of the enhanced stone. Tourmaline’s color can be enhanced through heat treating. Certain varieties become darker while others actually lighten. Tourmaline should not be cleaned in an ultrasonic cleaner, especially if the gem has been enhanced in any way.

More about Tourmaline the October birthstone

Ancient cultures attempted to explain the wide variety of colors in tourmaline. According to Egyptian myth, tourmaline passes over a rainbow on its journey from the center of the Earth, therefore taking on multiple colors along the way. While Tourmaline is a fairly hardy gemstone, it is best to clean jewelry with this gemstone using mild dishwashing detergent and water. Ensure jewelry is completely dry before storing or wearing. It is also recommended to not expose Tourmaline to drastic temperature changes as this may cause the internal structure to fracture.

The American Gem Society's October Birthstone page has more information to help you buy from knowledgeable and skilled jewelers and to help you make the most informed buying decision.