One of the most unique gemstones in the world is the famous Alexandrite. Named after Tsar Alexander II of Russia, this gemstone is a more recent discovery, having been first mined in the mid 1800's. It is a variety of the mineral chrysoberyl. Alexandrites are best known for both their intense color and dramatic color changes when viewed under different types of light. This is perhaps one of the main reasons Alexandrites have become such a popular stone worldwide despite their broad history compared to other gemstones. Other reasons for the Alexandrite's emerging popularity are their remarkable hardness and rarity compared to other gemstones.
Like nearly all gemstones, the primary characteristic for Alexandrite is color. An Alexandrite's color in sunlight varies in shades of green, with possible undertones of brown or blue. The most sought after Alexandrites have a deep green or blue-green color. However, the defining characteristic for Alexandrite is their color change. When moved from sunlight or fluorescent light to an incandescent light such as a candle, the mineral absorbs the light differently and the color displays differently. This secondary color can range anywhere from a brownish green to a beautiful red with purple undertones. This unique color change is due to the presence of irregularities from the trace element chromium. It's both the beautiful two colors and dramatic change between the two that makes it so popular around the world - it's almost like getting two gems in one!
On the Mohs scale of hardness, Alexandrites rank as an 8.5 out of 10, making it one of the most durable gemstones in the world. It is this durability that makes Alexandrite such a popular choice not just in necklaces and earrings, but especially engagement rings. Its association with luck, fortune, and love have only bolstered Alexandrite's popularity amongst newlyweds.
While all gemstones are rare to differing degrees, the Alexandrite is perhaps one of the rarest gemstones in the world. While Alexandrite mines exist in different parts of the world, the defining characteristics of what is considered an Alexandrite makes it difficult to find. Chrysoberyl, the mineral to which Alexandrite belongs, is already rare enough as it is. In order to be classified as Alexandrite, the gemstone must display a certain degree of color change; otherwise it is simply known as color-changing chrysoberyl. This rarity only adds to the mystique surrounding such a unique gemstone, and certainly makes it a popular choice amongst collectors and those wanting a unique and rare gemstone.
Quality of an alexandrite depends on three important factors: color (and color change), clarity and transparency. Pricing and quality are directly correlated, however origin, weight and treatment also substantially impact the value of an alexandrite, as discussed below.
Color and color change are the most important quality factors for an alexandrite and are the primary drivers of value. General rule is that as color saturation of an alexandrite increases, the value increases. The second and equally important factor is the color change. The more dramatic the change is between incandescent and daylight, the more valuable it becomes.
Below is GemsNY's own color change grading system for alexandrite:
|Intense -||These stones display the finest color change|
|Strong -||High degree of color change. Top 25% of all Alexandrites|
|Medium -||Average color change|
|Light -||Commercial quality color change. Still desirable due to the price point|
Colored gems do not have a standardized grading system and it is extremely rare to find an Alexandrite with no eye visible imperfections. This is in stark contrast to Diamonds which have a standardized grading system and require magnification to inspect clarity. In the wholesale trade we evaluate alexandrite clarity using the following methodology::
(1) Holding the alexandrite face up 12 inches from the observer's eye (2) Tilting the stone in various directions to visually inspect if any inclusions are visible (3) Only imperfections viewable on the crown (top part of the gemstone) are inspected and not the pavilion (back side)
Below are the clarity gradings for alexandrite we utilize and are commonly used by most of our jeweler customers:
|Eye Clean||100% clean to the eye, but not necessarily under magnification|
|Very Slightly Included||Very tiny inclusions are eye visible under close inspection or when tilting the gem|
|Slightly Included||Tiny inclusions are eye visible|
|Moderately Included||Inclusions are eye visible|
|Included||Significant inclusions are eye visible|
Lapidaries cut alexandrites according to the shade of the rough material to get the desired color (the primary price driver). Darker material is cut shallower to allow more light to go through the gem, while lighter material is cut deeper to allow the alexandrite to hold in more light and increase saturation. The lapidary also must factor in the color change when cutting the gemstone. Alexandrites also possess unique cleavage properties that makes it difficult to cut. Cutting alexandrite is an art and requires years of experience.
Transparent gems are the most valuable and allow one to see the true richness of color. The catch-22 with transparent gems is that it is much easier to view imperfections. Finding an alexandrite transparent and eye clean is truly rare. Over-saturation of color leads a gem to be semi-transparent as less light is allowed to escape. Opaque gems tend to be eye clean, but may appear as black.
The weight of a gemstone is measured in a unit called carats (cts.). There are 5 carats in 1 gram. As discussed above, an alexandrite can be cut deep or shallow to maximize the color of the sapphire. A deep cut 1 carat alexandrite will appear visually smaller than a 1 carat shallow alexandrite. For this reason, it is best to judge an alexandrite based on millimeter measurements (length and width) and not carat weight.
Click here for our Stone Size Chart which you can print to see the actual sizes of various shapes
Click here for our Stone Size Tool where you can input various measurements to see a basic rendering of centerstone sizes relative to your finger - particularly useful if you are planning to mount the gem in a ring.
Please Note: The carat weight listed on the website for pairs is the combined total weight of the two gemstones.
Alexandrites are mined in various locations around the world. All origins produce high and low quality gemstones. The origin of the alexandrite can have an impact on its value, primarily in the higher quality. Low quality alexandrite will not receive a premium even if they are mined from a rare and prestigious origin. See below various origins alexandrites are mined from:
|Russia||Very prestigious origin producing top quality alexandrites. Original alexandrites were sourced from Russia but there are no new gems being recovered from the region.|
|Brazil||Very prestigious origin producing top quality alexandrites.|
|Ceylon||Typical color change tends to be greenish yellow to brown color change. Green to purple color changes do exist.|
|Africa||Typical color change tends to be greenish yellow to brown color change. Green to purple color changes do exist.|
|India||Typical color change tends to be greenish yellow to brown. Green to purple color changes do exist.|
Alexandrites from Russian and Brazilian mines carry a premium over Alexandrites from other origins. The premium grows as the quality and size/weight of a gemstone increases.
There are no accepted treatments for alexandrites - they are typically found and sold as untreated. Any treatments applied such as dying will have a downward effect on price and should be avoided by customers.
Many local jewelers use a letter grading system to educate their customers of quality. To assist our customers to relate to the jewelers grading system, we have provided an overall grade. Please see the full grading scale and description below:
|Grading||% of All Alexandrite||Description|
|AAAAA (Collector Gems)||Extremely Rare||
These alexandrites are of Brazilian or Russian origin and are the rarest and highly sought out by collectors. They have rich color and 90 to 100% color change, very slightly included to eye clean clarity and exhibit nice sparkle. These gems tend to appreciate most in value over time due to rarity and high demand....View More
|AAAA (Heirloom)||Top 1%||
Fine quality alexandrites that are typically found at higher end boutiques. They have rich color and 80 to 100% color change, very slightly included to eye clean clarity and exhibit nice sparkle....View More
|AAA (Excellent)||Top 10%||
High quality alexandrites that are typically found in high end stores such as on 5th Avenue. They have medium to intense color change and slightly included to very slightly included eye clarity....View More
|AA (Very Good)||Top 25%||
These gems have medium to light color change and typically have moderate to slightly included eye clarity.These gems are usually found at medium to high end jewelers....View More
|A (Good)||Top 50 to 75%||
These gems have light color change and tend to be included. Typically found in commercial quality jewelry....View More
Alexandrites are very easy to take care of due to their hardness and durability. To keep your alexandrite jewelry sparkling you may want to clean it to remove the unwanted dirt and residue build up. Here are a few care tips to keep your alexandrite jewelry clean and shiny.
1) Avoid contact with make-up, harsh chemicals (i.e. chlorine and bleach), moisturizers and abrasives. It is best to take jewelry off when in contact with these items. Never swim or bathe with your jewelry on. It is also best to avoid hard impact activities such as exercising and gardening that may scratch or chip the alexandrite. 2) Clean your alexandrite by pouring lukewarm water in a bowl and mixing with mild cleaning detergent. Submerge your jewelry until the dirt and residue are moistened. Then use a soft toothbrush to clean the underside of the sapphire. Once clean, rinse and dry with a soft cloth. For extremely dirty jewelry, you may need to repeat the process. 3) Store your alexandrite jewelry individually and avoid contact with other jewelry to prevent scratching. For every day rings (such as engagement rings), we recommend a weekly rudimentary check to ensure the center gem is not loose. Take off the ring and shake it next to the ear (can also tap) and see if you hear rattling. If you do, immediately stop wearing it and get it tightened. 4) We highly recommend an annual maintenance of your alexandrite jewelry to have the gems tightened and jewelry cleaned professionally. This will ensure your jewelry lasts a lifetime.