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(this page is largely unformatted due to time constraints. for now.)
Under fluorescent light: dark (bluish) Green
http://www.airtron.com/synoptics/stanprod.htm#laserrods
Laser wavelength range: 710 to 800 nm
Crystal Structure: Orthorhombic
Melting Point: 1870C
Hardness (Vickers): 2000 kg mm-2
Hardness (Mohs): 8.5
Formula:
Be (Al Cr ) O
1-x x 2 4
http://pioneergem.com/Alexandrite.html
3.50 mm Round 0.20cts $200.00
5.4x4.5 mm Pearshaped 0.37cts $296.00
Alexandrite is a special kind of stone which can change its color in
different light. In this story Alex's mother give him a ring which belonged
to his father. Alex know nothing about his father other than his name is
"Alex" and he is from Greece.
Price: ~$950 to ~$2200 per carat.
http://valleyjewelers.com/fx070006.htm
Alexandrite is an extremely rare gemstone of the chrysoberyl species,
which was first discovered in the Ural Mountains of Russia in 1830, on
the day that Prince Alexander (later Alexander II) came of age (the old
Russian imperial colors are red and green). In daylight (or fluoscent
light) it can appear almost emerald green, but is more often blue green
to yellowish green. Under incandescent light, the finest gems appear red
to purplish red, although most stones appear in the pinkish brown to
reddish brown range.
Then in 1987, a new find of alexandrite was made in Brazil at a locality
called Hematita. The Hematita alexandrite shows a striking and attractive
color change from raspberry red to bluish green. Although alexandrite
remains extremely rare and expensive, the production of a limited amount
of new material means a new generation of jewelers and collectors have
been exposed to this beautiful gemstone, creating an upsurge in
popularity and demand.
When evaluating alexandrite, pay the most attention to the color change:
the more dramatic and complete the shift from red to green, without the
bleeding through of brown from one color to the next, the more rare and
valuable the stone. The other important value factors are the
attractiveness of the two colors - the more intense the better - the
clarity, and the cutting quality. Because of the rarity of this gemstone,
large sizes command very high premiums.
http://www.chatham.com/mainalex.html
Alexandrite is a form of the mineral chrysoberyl. The best naturally
occuring alexandrites still originate from Russia, but they are becoming
increasingly scarce and are therefore extremely expensive. Now, created
alexandrites of distinctive beauty and exceptional quality are available
from Chatham at a very affordable price.
The first company in the world to produce created emeralds, rubies and
sapphires, Chatham once again set a precedent when it developed a process
for growing alexandrite crystals within a laboratory setting in
1975. Currently grown in Russia, Chatham-created alexandrites are not
imitations and bear the same properties as their natural counterparts. Only
a trained gemologist using proper equipment can distinguish Chatham from
natural alexandrites by examining the "inclusions" in each stone.
Chatham will replace broken or chipped Chatham-created gemstones.
Jewel, mount, proof-of-purchase, cover-letter, and valuation must be sent.
http://www.nashville.net/~ggolden/alex.htm
Today, Russian deposits produce very little, which leaves Brazil and Sri
Lanka responsible for supplying the majority of alexandrites to the
world. Other sources include Burma, Tanzania, and Zimbabwe.
(natural) Oval, 0.6 ct, 5 3/4 X 4 mm, dark green to purple, $9k/ct
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