Product Details
Stone type: Tourmaline
Weight: 12.15 ct
Dimension: 19.50X13.50X7.50 mm
Color: Green/Black
Shape & Cut: Oval, SHA cut
What is Tourmaline?
Tourmaline is a crystalline silicate mineral group in which boron is compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. This gemstone comes in a wide variety of colors. The name is derived from the Sinhalese tōramalli, which refers to the carnelian gemstones.
Tourmaline is Which Month's Birthstone?
Tourmaline is the newer October birthstone. The name comes from the Sinhalese word toramalli, which means “stone with mixed colors,” because it often has multiple colors in one crystal.
What is the unique Quality of Tourmaline?
Color
One of tourmaline’s most sought-after and generally available colors is the pink/red variety known in the trade as rubellite.
Green tourmaline’s pastel hues provide the market with pleasing alternatives to the deep, rich hue of emerald and the softer green of peridot. At their best, green tourmalines are transparent, brilliant, and clean, with attractive bluish green hues.
Most green tourmalines are strongly pleochroic. Stones that show attractive colors in both directions—such as bright green in one and blue in another—are the most valuable.
Chrome tourmaline gems offer hues that are more saturated than most green tourmalines. Chrome tourmaline can be a lower-priced alternative to tsavorite or emerald. Both these gems are rare in sizes above two carats, but it’s not hard to find chrome tourmaline in sizes up to five carats. And, while tourmaline can’t match tsavorite’s luster or brilliance, it’s far less expensive than a tsavorite of equivalent size and quality.
Dark-toned stones—which are more common in the marketplace—aren’t very attractive. Some absorb light so intensely that they appear almost black from certain directions. Cutters typically fashion these stones with the table parallel to the length of the crystal. Gems cut this way might show a less attractive brownish or yellowish color through the crown. Dealers frequently describe these gems as “oily” or “olive” green. Their prices are much lower than the prices for fine green tourmaline or brighter bluish green tourmaline.
BIO COLOR
Watermelon, bicolor, and multicolored zoning occurs when the trace elements change in concentration or composition during a crystal’s growth. Liddicoatite can show striking and complex zoning, and gems are often fashioned to showcase exotic color combinations. Gemologists describe these tourmalines as parti-colored.
CATS EYE
Dealers usually tolerate red tourmalines with some eye-visible inclusions as long as the color is strong and attractive. Inclusions that reach the surface interfere with luster and polish and make gems harder to sell. And although liquid inclusions are less visible in stones of intense color, stones with prominent whitish inclusions—no matter how vibrant the color—are undesirable.
Inclusions are much more visible in gems with light tone and low saturation. Since these stones don’t have strong and attractive color to compensate for the inclusions, most buyers reject the ones with eye-visible inclusions. Many included tourmalines with good color are cut as cabochons to emphasize the color and minimize the appearance of the inclusions.
It’s not unusual for pink and red tourmalines to have eye-visible inclusions. Unless their size or the number of the inclusions is distracting, knowledgeable consumers consider the color to be the dominant value factor. Green tourmalines are expected to be free of eye-visible inclusions so distracting inclusions can lower the value of the green gems. For the other colors, tourmalines with no eye-visible inclusions are more valuable than those with inclusions that can be seen. The more visible any inclusions are, the more the value drops.