by Ron Campbell Central Coast Gem Lab
As of late, (the past four years,) there has been an influx of color change chrysoberyl. Their origin has been from various areas of South America, East Africa, and Sri Lanka Their color change typically ranges from Green to yellow, Brownish red to purple, yellow Green to bluish green. Other combinations are occasionally seen as well.
- Note: In color descriptions, a capital letter on one hue means it is the dominant color. Those beginning with a lower case letter are the less dominant or secondary color. So, when you see the color description written as; Green yellow, or Red purple, this tells you which is the dominant and which is the secondary color.
These have been marketed as Alexandrite and commanded very high to moderate prices. While they have a dramatic color change, they should not be considered as alexandrite.
To a gemological laboratory, there are strict standards of color change that have to be met and observed before a chrysoberyl can be graded as an Alexandrite. It is important to note what the color range has to be before a chrysoberyl can be called an alexandrite. Here is the classic definition of alexandrite’s color change ranges: *
|Daylight (sunlight)||Incandescent light|
|blue Green||orange Red|
|very slightly blue Green||Red|
|Green||slightly purple Red|
|slightly Green||Purple Red|
|yellow Green||Red purple or Purple red|
You should not have to guess about these color changes, nor should the color change be feeble. The color change is very dramatic and with out question. Any of these combinations that are observed in a particular chrysoberyl can and should be identified as alexandrite and graded as so. No other color combinations should called or graded as alexandrite but as color change chrysoberyl.
Historically the origin of fine grade alexandrite has been from the Ural Mountains. However, recent finds of good material from Brazil and some East African countries, exhibit a good to fine color change in the prior described color ranges.
Do not be fooled into purchasing a color change chrysoberyl in place of the alexandrite. (Many of these stones can be seen on various T.V. shopping networks.) The price should be your first clue; just a good grade of alexandrite, in a size range of 1-2 carats, can demand a $2,500 per carat wholesale…. Note the color change description next. Bear in mind that, if the color change does not match the above, when sent to a gemological laboratory, it will not grade out as alexandrite.
Let me add this gem of information, (excuse the pun.) A color change chrysoberyl is not a common stone and also demands a hefty price. They are a great addition to any gemstone collection, but do not pay for an alexandrite when you not getting one. Buyer beware! Knowledge is power and your best gemological tool to keep from being disappointed and keeping your hard earned dollars.