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. AURIC JEWELS 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.
