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SAPPHIRE
 Color
is of paramount importance when judging the value
of sapphire. The purer the blue of a natural sapphire,
the greater the price the gemstone can command.
Gems that are too dark or too pale are usually
less valuable, but not necessarily less appealing.
Beauty is in the eye of the beholder and color
preferences are subjective.
In recent years technology
has perfected the process of heat-treating sapphires--exposing
them to very high temperatures to eliminate impurities.
In fact most sapphires on the market today have
been heat-treated to improve clarity and color.
This process is stable and does not affect the
value of the gem, except at the highest level
of the market.
Occasionally, colorless
to pale blue sapphire is diffusion treated. This
process alters the color of a gem by exposing
the surface to certain chemicals (the same used
by nature). The treatment is fairly stable, but
it is confined to the surface of the gem only.
This could create a problem, if the sapphire is
ever badly chipped or nicked and needs to be recut
or repolished. Diffusion treatment is not the
same as heat treatment. My Jewelz only sells natural
or stable, heat-treated sapphires of exceptional
color in our Gem Store exclusive collection.
Additionally, some fancy
sapphire is irradiated to produce intense shades
of yellow or orange. This process, however, is
not very stable. The temporary color produced
by this method can quickly fade in light or heat.
It is important to buy fine sapphire from a reputable
retailer who will provide, in writing, all pertinent
information regarding the gem including enhancements
and special care notes.
A gem's clarity and
cut also factor into its cost, as well as carat
weight. Better quality sapphires are usually eye-clean
with some inclusions under magnification. Sapphire
is more available in sizes under two carats, but
gems of 5 to 10 carats are not unusual. Sapphire
reaches a far greater size than ruby.
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