Alexandrite from any source is one of the world's rarest gems.
Reportedly, this gem was discovered on Czar Alexander the Second's birthday in Russia in 1830, and hence its name. This is one of the few gems that actually change color. The stone appears green like an emerald in natural daylight, and ruby red in artificial light.
Interestingly, these were the colors of the Russian Imperial Guard. The major deposits of alexandrite in the Ural mountains were depleted long ago. Tiffany was instrumental in marketing Russian alexandrites to Americans during the late 19th and early 20th centuries. Tiffany liked to sell large alexandrites that were mounted as center stones. Most of these stones are in family vaults and are passed from generation to generation. These stones are extremely difficult, if not impossible, to buy today. Sometimes, Victorian jewelry can be found with smaller alexandrites.
Today, the main sources of alexandrite are Sri Lanka, Madagascar, Tanzania, India, Africa and Brazil. In 1987, a new find of alexandrite was discovered in Nova Era, Brazil. Until this find, Brazil had always been known as a producer of inexpensive gems. Presently, there is some new limited availability of these goods. A new person has taken over the old Hematita mine and they are mining deeper into the mountain. No one knows how much more the deposit can produce but the material presently is high quality.
A color change gem is a stone that changes from one color to another color depending upon the light source. Color changes are complicated science. In a nutshell, the color change which occurs in alexandrite is probably the result of the presence of chromium and its effect on the way light is absorbed and reflected.
In an ideal perfect world, alexes change from red to green. However, this is not usually the case. They tend to change from a brownish reddish raspberry to a grayish bluish green. Some stones only partially change color. What you are looking for is a dramatic 100% change. When buying alexandrites, remember the color change is the most important factor in determining the value of the gem. What was amazing about this find is many of the top Brazilian gems have a dramatic color change. Although they did not change from ruby red to emerald green, they change from a pleasing raspberry red/pink to an indicolite blue/green color. As a general rule, if the blue side is good the red side is good. If the blue side is greenish, the red side is a lighter raspberry pink. Beware of alexandrites that "bleed", or you can see the two colors at the same time under a single light source. You are also trying to minimize gray or brown in these stones. Clarity is a minor issue, as long as the inclusions do not affect the gem's durability. Although the color change represents the majority of the value of a color change gemstone, do not forget that brilliancy, cutting and finish also affect the gem's final price. The more vivid the colors of a color change, the more valuable the gemstone. Ideally, you want a dramatic color change with a medium tone and intense color.
The two main markets for the material are manufacturers and collectors. Natural alexandrites are one of the most sought after gems by collectors.
Prices for the new material range the entire gamut. For example, jewelry manufacturers can obtain the material in 2 mm rounds for only $250 per carat. Carat sized alexandrites start in the $3000 per carat range. Fine and large 5-8 carat sized alexandrites can easily reach $25,000 per carat. An 11.08 alexandrite sold for $382,680 or nearly $35,000 per carat to an Asian buyer in 1998 at Christie’s. Any alexandrite over 10 carats is beyond rare. The most famous alexandrite is the 66 carat Sri Lankan gem currently in the Smithsonian Institute. These stones are most commonly cut into ovals or cushions with an occasional round or emerald cut.
Gems that show unique optical effects are known as phenomenal stones.
Alexandrite is a phenomenal stone and a gem variety of the mineral chrysoberyl. It is a hard stone with a Mohs of 8.5 and no special care is needed in handling the material.
Imitations and Treatments
Many in the jewelry industry have had clients bring in “supposed” natural large alexandrites into their stores. Usually the stone arrives with a great story of how it was purchased years before overseas and the stone is worth undoubtedly a great deal of money. In most cases, however, the stones are actually synthetic color-change sapphires colored by vanadium. These synthetic color-change sapphires have been made since the early 1900’s and are only worth worth few dollars per carat.
While it is unusual to find a treated alexandrite, sometimes oiling is seen. Of more concern is the fact excellent synthetics do exist. Consider an independent lab report for an expensive alexandrite.
This is an excellent stone to collect for your portfolio. if you have sufficient funds, we recommend this gemstone now while there is some production. The last supply was short-lived.