alexandrite displays a colour
change (alexandrite effect) dependent upon
the light source under which it's viewed.
Alexandrite results from small scale replacement of aluminium by
which is responsible for alexandrite's characteristic green to red
colour change. Alexandrite from the
Russia is green
by daylight and red by incandescent light. Other varieties of
alexandrite may be yellowish or pink in daylight and a
by incandescent light. The optimum or "ideal" colour
change would be fine emerald green to fine purplish red, but this is
00000Because of their
rarity and the colour change capability,
"ideal" alexandrite gems are some of the most expensive in the world.
The are many lesser quality alexandrite on the market, usually pale
green and not displaying a noticeable colour change.