Blue Tourmaline (Indicolite) Buying Guide
All tourmaline gems wear well in almost any type of jewelry setting. Blue-colored tourmaline gems, also known as indicolites, are a very popular choice. To help your shopping go smoothly, I’ll share my personal opinions and experiences dealing with blue tourmalines.
Indicolite Buying and the Four Cs
Indicolites can range from light to dark saturated blue. Although color grading is a judgment call, I think many tourmalines sold as blue are misrepresented. In my opinion, an indicolite can be any shade or color as long as blue predominates. For example, most indicolites have some degree of green in them. (See below). I would call a blue/green stone with dominant blue a blue tourmaline. If the green dominates, I’d call it a green tourmaline or verdelite. Generally, blue brings more money, which explains why some in the trade are eager to call blue/green tourmalines indicolites even if the green predominates.
Of course, most tourmalines receive heat treatments, which can remove or lighten any green tones.
The well-known paraiba tourmaline possesses the top color for all blue tourmalines. These copper-bearing stones can show a neon blue. Its price per carat, up to two carats in size, can reach $8,500. In contrast, other top-quality blue tourmalines of similar size may only reach about $500 per carat. (These gems merit a separate buying guide).
Blue tourmalines are considered Type II clarity stones. Typically, they possess inclusions. Stones with high grades such as IF (internally flawless) to VVS (very, very small inclusions) are rare. Of course, you can find lower clarity material more readily in the commercial market.
You can find cut indicolite gems in many styles. Cutting affects the value of the finished stone significantly. If you’re buying a cut stone, ask yourself: is it cut to high custom standards? Or, is the stone cut to average commercial quality?
Please note, you’ll encounter different levels of commercial cutting. While nowhere near top custom-cut quality, some commercial cutting beats out low-quality commercial cutting. Signs of quality commercial cutting include:
You can purchase blue tourmalines in just about any size range, depending on your budget.
Indicolite Gemstone Treatments
Most cut blue tourmalines on the market receive heat and radiation treatments. Although very common, the industry often doesn’t disclose these practices. Be aware of a heated and irradiated light blue tourmaline marketed under names like “Blue Ice.”
How can you protect yourself from undisclosed treatments? First, do business with reputable, experienced gem dealers who cut their own stones. Second, look for these clues.
- If the stones you’re examining have the same color tone and look, they could be irradiated. Untreated gemstones seldom look exactly alike. Trays of identical stones are a pretty obvious tip-off.
- If the indicolites you’re examining lack any color shift, they could be treated. Typically, untreated stones will change a little as the light changes.
Synthetic tourmaline isn’t commercially available. However, simulants (imitations) do appear for sale occasionally. Quartz, natural or synthetic, can be stained or dyed to resemble tourmaline. You may also encounter synthetic spinel misrepresented as tourmaline. Of course, some verdelites may be passed off as blue tourmalines, too.
Does the Origin Affect the Value of an Indicolite?
In some cases, a gemstone’s source can affect its value. However, a blue tourmaline’s origin normally doesn’t factor into value. Of course, gem collectors may want to know this, and it’s always nice to know where a stone was mined.
However, the question of a paraiba tourmaline’s origin can be of great interest. Some collectors argue that a stone’s color and chemical composition make it a paraiba whether it comes from Brazilian or African sources. Others hold that only copper-bearing tourmalines from Paraíba, Brazil deserve that appellation. Of course, making that distinction can be difficult.