Modified: November 2012
by Gavin Linsell, Zultanite® Marketing Director
The color changing variety of the mineral diaspore, Zultanite® is a new gemstone that is beautiful, rare, never treated and is ethically mined with environmentally safe techniques. Zultanite’s extreme rarity is easy to explain – it only comes from one mine in the whole world located at a height of over 4,000 feet in Turkey’s Anatolian (Ilbir) mountain range. Curiously, Zultanite® is an older ‘new’ gem; discovered in the early 1950s, it has only been commercially mined since 2006. Zultanite® was named in honor of the 36 Sultans who ruled the Ottoman Empire (1299 - 1923), prior to the formation of the modern Republic of Turkey. Truly a ‘Sultan of Gems’, Zultanite’s big appeal is its ability to show different colors when viewed under different light sources, such as sunlight (candescent light) and candlelight (incandescent light). While color change is an uncommon optical phenomenon in gemstones that increases their rarity, desirability and value, actually seeing color change can sometimes be challenging, especially if unrealistic expectations cloud your approach. Read on to discover the amazing properties of this color chameleon and how to best appreciate them.
A very rare and beautiful optical property that is part of a gemstone’s structure, color changing gems can be counted on one hand: Alexandrite, Color Change Fluorite, Color Change Garnet, Color Change Sapphire and Zultanite®. OK, they’re rare, but how does this all work?
As revealed by rainbows and the fire in Diamonds, white light is comprised of the individual colors of the spectrum: blue, green, orange, red, violet and yellow. When white light passes through a gem, some of these spectral colors are absorbed. The spectral colors of white light least absorbed combine to produce the color of the gem. This absorption of certain colors is called the ‘selective absorption of light’ and is always the same for an individual gemstone. It is changes in a light source’s component colors that cause gems to look different in various lighting conditions. Although they appear similar to our eyes, sunlight has very strong green wavelengths, while candlelight is richer in red wavelengths. In color change gems, absorption of different colors of the spectrum from different light sources results in our ‘color change’ perception. As with all optical effects, color change is more noticeable and displays greater color intensity in bigger gems. Color change gems are judged by the strength of the color change, and how attractive and distinctive their colors are in candescent and incandescent light.
This leads to a unique property of Zultanite®; when it comes to light, this phenomenal gemstone is definitely a sensitive soul. Unlike other color changing gems, Zultanite’s color change is not limited to two basic colors. Its contrasting colors change from kiwi greens with flashes of canary yellow under sunny skies, to rich champagnes in traditional indoor lighting and raspberry hues in candlelight. All Zultanite® crystals have a well-developed color change observable under different light conditions as well as from different angles. This is because Zultanite’s color change effect combines with its pleochroism (different colors visible from different angles) to produce the selective absorption of light. This means a wide variety of other colors may occur with alternate illumination and different angles. The same Zultanite® can exhibit sparks of canary yellow, cognac pink, ginger, kiwi green, raspberry pink, rich champagne and sage green.
“Emerald” by day and “Ruby” by night, Alexandrite is the quintessential color changing gemstone that started interest in this phenomenon. So much so, that color change is also known as the ‘Alexandrite Effect’. I hate to play favorites, but Alexandrite comparisons illustrate the uniqueness of Zultanite®. While their colors can be similarly dramatic, Zultanite® is differentiated by its plethora of light sensitive hues, high scintillation (play of light) and the fact that it’s best color changes are not dependent on dark tones. Ideally, a gemstone’s colors should remain beautiful in any light source. Good-looking colors that dramatically change are the pinnacle for Alexandrite and this is where it sometimes runs into problems. As most of us live in places where mixed lighting is the norm (illumination from several sources, such as a mix of sunlight shining through windows combined with indoor lighting), ‘bleed’ (both colors visible at the same time) commonly occurs in Alexandrite. Given that its darker tones offer a better change, a loss of brilliance and beauty often occurs. Compared to Alexandrite, Zultanite® loves mixed lighting and can display all its colors simultaneously without losing brilliance. This inherent light sensitivity also places Zultanite® within the highly desirable group of gemstones whose colors suit all complexions, fashions, personalities and styles.
This sounds great, but actually seeing change color in Zultanite® is dependent on several factors: the intensity and purity of the light sources, your eyesight, pleochroism, time of day, and even the weather. Zultanite® is an experiential gemstone; try viewing the gemstone in a variety of different environments over a 24-hour period. For example, outdoors at a picnic, an afternoon indoors watching TV, and then in the evening during a candlelit dinner. Standing under kitchen fluorescents with a cigarette lighter is not the best viewing environment. Scrutinizing Zultanite® in a variety of different lighting environments is definitely a good idea and will reveal the appealing nuances and subtleties of its color change. Just remember, that while the color of Zultanite® is fairly homogeneous, size and cutting quality accentuate its color intensity and visible color change, with smaller gemstones being lighter in color. Expert lapidary brings out Zultanite’s color change to its fullest and this is why Zultanite® with our Authenticity Guarantee (pictured) is always optimally cut and eye-clean (no visible inclusions when the gem is examined approximately 6 inches from the naked eye).
So take the plunge, and get ready to discover why Zultanite’s beguiling color palette, combined with an exotic pedigree, has made it a favorite among jewelry connoisseurs around the globe.
An Australian gemstone writer, expert and adventurer who has lived in Thailand for over a decade, Gavin Linsell is the Marketing Director for ZULTGEMS, the authorized Zultanite® distributor since 2010. He is the author of two gemstone books, Guide to Gems & Jewelry and The Clever Gem Buyer. Apart from traveling extensively to gem markets and mining centers in Asia, Africa and South America, Gavin is also a member of the ICA (International Colored Gemstone Association), an organization whose members include the top gemstone miners, cutters and dealers throughout the world.