Alexandrite / Chrysoberyl
ALEXANDRITE / CHRYSOBERYL TECHNICAL DATA
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Species---------------------- Chrysoberyl
Chemical
Formula-----------BeAl2 O4
Birthstone----------------------------June
Anniversary
Stone---------Eighteenth
* Mohs
Scale Hardness------------# 8.5
Durability-------------------------Excellent
* Refractive
Index----------1.746-1.755
* Specific
Gravity-------------------3.73+/-
Significance
of these* data (FAQ # 5)
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ALEXANDRITE / CHRYSOBERYL ADDITIONAL INFORMATION
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Color
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Chrysoberyl is normally encountered cut as a Cat's
Eye cabochon in a yellow to a green hue.The color change variety known as
Alexandrite will usually exhibit a blue/green color when viewed under a cool
light source such as most fluorescent lights. Under a warm light source such
as an incandescent bulb, sunlight or candle light the color will change to a
red/purple hue.
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Sources
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The original source of Alexandrite was Russia
which is still a producer of fine material. Sri Lanka also became a source of
this rare gem. In the last 20 years Brazil has become a supplier of commercial
quality material.
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Treatment
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Neither Chrysoberyl nor Alexandrite are usually
treated or enhanced. However, one should be aware of a very fine synthetic
(FAQ # 8) Alexandrite manufactured in Japan which has infiltrated the
market. All of our material is natural.
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Care
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Chrysoberyl without flaws is very durable.
However, any Cat's Eye gemstone, or any gemstone with inclusions, should not
be subjected to high heat such as from a soldering torch which would cause the
stone to crack. Similarly, ultrasonic or steam cleaning is risky with any
included gemstone.
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Alexantrite Cat's Eye
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Until recently Cat's Eye Alexandrite was not known
to exist. A Canadian gem dealer acquired a badly worn piece of estate jewelry
which when repolished proved to be a Chrysoberyl Cat's Eye with a significant
color change ie an Alexandrite Cat's Eye. This was later confirmed by GIA. We
have 2 small examples in our price tables.
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Uses
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Both Chrysoberyl and Alexandrite are durable
enough for both mens' and ladies' rings, pendants and earrings.
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Value
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Both Chrysoberyl Cat's Eye and natural Alexandrite
are extremely rare and fine material with pronounced color change is very
expensive. Our Brazilian Material is more moderately priced. We select our
gems so that they do have a color change and any visible inclusions are
minimal.
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Color Change
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In the examples below we have photographed some of
our Alexandrites using first a standard white floodlight and secondly a cool
white flourescent
light source which shows the color
change under various light conditions.
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RETURN TO ALEXANDRITE
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