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Bright, vivid, showing an excellent green
and a strong color change to a hot pinkish red.
A rare and highly collectable variety of chrysoberyl, alexandrite
ranks alongside ruby and padparadsha as the world’s most desirable and expensive
colored gemstones. Discovered in 1830 on the silver birch clad banks of
Russia’s Tokovaya River, this extraordinary gem was named after the young
Czarevitch, Alexander Nicolajevitch who would later become Czar. For over
100 years now, alexandrite has commanded the higher positions in the pecking
order of gemstone desirability.
Scant availability combined with remarkable color change,
excellent durability and a sparkling adamantine luster,
alexandrite is an excellent gem for
the connoisseur. However, while ranked as one of the world’s most desirable
and expensive gem types, it must be born in mind that not all alexandrites
are of a comparable quality. Understanding exactly where value lies in
this extraordinary gem type is essential to be able to make accurate quality
appraisals, or make safe and rewarding purchases. |
| The
Three Colors Of Alexandrite? |
Like
most other gemstones, the quality of color in alexandrite is
the all-important factor. However, with alexandrite there is
arguably three color factors that need to be considered within
a single jewel: the daylight color, the incandescent-light color,
and the degree of change between them.
Top quality alexandrite exhibits an attractive metallic bluish green color
under daylight. Free from being too light, too dark, brownish or gray,
the green color witnessed should be attractive within its own right.
Exactly the same principle of “attractive within its own right” should
also be applied to the reddish color seen under incandescent-light. It
too, should be free from being too dark, brownish or gray.
On top of these two color considerations is the
degree of change experienced between the two colors – the
greater the change, the more desirable the alexandrite.
However, all three factors should be accounted
for as a balanced
sum of three parts. A striking green alexandrite that shows a vivid color
change, is let down if the incandescent-light color is too dark or brown.
 Carat
Weight & The Pricing Of Alexandrites
As a rare gem in under supply and over demand,
alexandrite can be expensive. Fine quality specimens
under two carats are obtainable but costly. Large
alexandrites that go above the five or six carat mark are considered extremely
collectable and possess high ticket prices as the world’s wealthiest collectors
vie for highly desirable but scarce specimens.
Freedom
From Inclusions & The Pricing Of Alexandrites
As a gem that is noted to suffer from smallish
crystal sizes and tendencies for poor freedom from
inclusions, parallels can be drawn to ruby – prices
rise stratospherically as clean alexandrites go above the three carat mark.
Unlike its non-color changing brother chrysoberyl, alexandrite has been
placed in the Type II category of colored gems, meaning that inclusions
are typical.
Shape & Cut
Faceted alexandrites are found in wide variety
of shapes and styles. However, due to the high
expense of rough alexandrite, the shape of “native cut” polished
gems are often tightly bound to that of the rough gem. As a consequence,
alexandrites are regularly submitted for recutting, which pushes per carat
prices up even further as the strive for perfection dictates a second visit
to the polishing wheel and the inevitable weight loss it entails.
While oval and cushion cuts are the most frequently
seen alexandrite cuts, other shapes such as emerald
and heart cuts are also relatively common.
Large round cut alexandrites are seldom seen as high rates of weight loss
during cutting push already expensive per carat prices up even further.
Cabochons are most regularly seen in cat’s eyes and star alexandrites.
Cat’s
Eye & Star Alexandrites
Cat’s eyes and stars in all gem varieties have long been coveted for their
beautiful and mysterious optical effects. Glance at a cat’s eye alexandrite
and you will see a band of light silently gliding across the surface. Sometimes
a fainter second arm of light will intersect the bright band, creating
a color changing star alexandrite.
Sources
Of Alexandrite
Perceived as the finest locale for alexandrite, Russian origin specimens
possess a historical pedigree that means some people are prepared to pay
a premium for them over alexandrites of other origins. In reality, alexandrites
every bit as fine have been unearthed in Burma, Brazil, Sri Lanka, India,
Madagascar, Tanzania and even Zimbabwe.
The spectacular and massive 15.58 Carat certified alexandrite. A gem such
as this is destined for the hands of a private collector.
Today, Tanzania and Madagascar are responsible for a large proportion of
the alexandrite on the market. Both locales can produce exceptionally fine
specimens such as this huge 17.90 mm x 11.83 mm certified 15.58 Carat Tunduru
alexandrite featured left. Also, increasingly found on the market in the
last few years are fine quality specimens from Andrapradesh, India.
As a rare gemstone, alexandrite is a highly desirable product that is sold
at a premium. While the desirable features of an alexandrite are the three
color factors, just like other gemstones, attributes such as carat weight,
clarity, cut and origin also need to be considered. |
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