TOURMALINE: October Birthstone
Somewhere in Brazil in the 1500s, a Spanish conquistador washed the dirt from a green tourmaline crystal and confused the vibrant gem with emerald. His confusion lived on until scientists recognized tourmaline as a distinct mineral species in the 1800s. The confusion about the stone’s identity is even reflected in its name, which comes from toramalli, which means “mixed gems” in Sinhalese (a language of Sri Lanka). It’s a term Dutch merchants applied to the multicolored, water-worn pebbles that miners found in the gem gravels of Ceylon (now Sri Lanka).
WHERE IS TOURMALINE FOUND?
This October birthstone is most commonly found in Brazil, but it is also mined in Afghanistan, Pakistan, Kenya, Madagascar and Mozambique (among other countries in Africa). California and Maine are historically important producers of fine tourmaline in the United States.
Varieties of Tourmaline
Tourmalines come in a wide variety of exciting colors. In fact, tourmaline has one of the widest color ranges of any gem species, occurring in various shades of virtually every hue. Many tourmaline color varieties have inspired their own trade names:
- Rubellite is a name for pink, red, purplish red, orangy red, or brownish red tourmaline, although some in the trade argue that the term shouldn’t apply to pink tourmaline.
- Indicolite is dark violetish blue, blue, or greenish blue tourmaline.
- Paraíba is an intense violetish blue, greenish blue, or blue tourmaline from the state of Paraíba, Brazil.
- Chrome tourmaline is intense green. In spite of its name, it’s colored mostly by vanadium, the same element that colors many Brazilian and African emeralds.
- Parti-colored tourmaline displays more than one color. One of the most common combinations is green and pink, but many others are possible.
- Watermelon tourmaline is pink in the center and green around the outside. Crystals of this material are typically cut in slices to display this special arrangement.
MOST POPULAR TOURMALINE COLORS
At our jewelry store in Boca Raton, we have found that the two most popular colors of tourmaline that people have been requesting in jewelry are: Paraíba Tourmaline and Watermelon Tourmaline.
Paraíba Tourmaline is an elbaite tourmaline that comes from one area of Paraíba state in Brazil’s northeast corner. Like many other Brazilian elbaites, Paraíba tourmaline forms in pegmatite. But researchers believe that its crystals form under very unusual conditions, with large amounts of trace elements like manganese and copper, which causes its color. Paraíba tourmaline is unusual because, although copper colors some other gems—notably turquoise—it’s not a coloring agent in any other tourmaline. Paraíba tourmalines appear in a range of greenish blue, bluish green, green, blue, and violet hues. Overall, prices for the best Paraíba tourmalines easily surpass other tourmalines due to their more attractive hues, higher color saturation, and greater rarity. Prices for this exotic newcomer—especially top quality in sizes between 3.00 and 5.00 carats—climbed rapidly to over $10,000 per carat. No tourmaline—even prized rubellite reds and chrome greens—had ever achieved such heights in value.
Tourmaline Quality Factors
- 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 tourmalines—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.
Blue tourmaline can range in tone from light to dark. The hue is often modified by green so you can have a blue color with just a little bit of green modifying color or a color that is very greenish but still blue. Some tourmalines have an even amount of green and blue to the color. Like green tourmaline the blue colors can be strong and vivid or less saturated and grayish.
- Since it was discovered in the late 1980s, Paraíba tourmaline’s striking neon blues and greens have electrified the gem world. The gem’s unique, vivid coloring instantly set it apart from other tourmalines.
- CLARITY. Colored tourmalines grow in an environment rich in liquids, and some of those liquids are often captured as inclusions during crystal growth. The most typical inclusions resemble thread-like cavities that run parallel to the length of the crystal. Under magnification, you can see that they’re filled with liquid or gas bubbles. Growth tubes—long hollow tubes often capped with minute mineral crystals—are also common tourmaline inclusions. If they’re numerous enough, and the rough is correctly cut, they can cause a cat’s-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.
- CUT. The elongated shape of many tourmaline crystals has a direct impact on the finished gem’s shape and proportions. As a result, there are many narrow, non-standard sizes available. Although some are very attractive, many gem buyers prefer stones with standard dimensions because they’re easier to set in standard mountings. Cutters often fashion tourmalines as long rectangles. Making the cut parallel to the length of the rough crystal helps to reduce waste. But cutters also have to consider tourmaline’s optical properties.
- CARAT WEIGHT. Fashioned tourmalines in larger sizes rise considerably in per-carat price. Even though specimens can reach spectacular sizes, these are rare. Availability drops and prices rise sharply for facet-quality rough material. For fashioned gems of similar color and clarity, the price per carat generally increases as the gems pass the five-carat milestone.
Tourmaline Jewelry Care & Cleaning
The tourmaline birthstone is rated 7 to 7.5 on the Mohs scale of hardness and is generally suitable for everyday wear. These colorful gems are usually stable enough to withstand light and most chemicals, but heat can be damaging. This October birthstone is best cleaned with warm, soapy water and a soft brush. The use of ultrasonic and steam cleaners is not recommended.
Tourmaline Jewelry in Boca Raton
Now that you know a little bit more about the history of this October birthstone and where it can be found, you just might be inspired to add it to your collection! This birthstone comes in a spectacular array of colors sure to please you or your loved one born in October. Stop by our Boca Raton jewelry store to view tourmaline jewelry available in our showroom.