Gemstone
Enhancements
The term enhancement is defined as any treatment
or process other than cutting and polishing that improves the
appearance (color/clarity/phenomena), durability, value or
availability of a gemstone. In today’s gem marketplace,
many gemstones have been enhanced by a variety of methods.
Such processes may range from simple heating (such as with
tanzanite) to high-tech irradiation (such as blue topaz).
 At
the Collector, we take enhancement
disclosure seriously and guarantee,
to the best of our abilities, to provide
our customers with complete information
on any and all enhancements to which
a gem has been subjected. While many
enhancements are currently undetectable,
we do our best to provide all the information
you need for informed buying decisions.
The
guidelines we follow are those of the AGTA and
are the most stringent in the industry.
In addition, we have modified these
guidelines slightly in areas where
we feel they are not stringent enough
(example: flux healing of ruby).
Some
gemstone enhancements are less stable
than others, meaning that the appearance
of a gem may change with time. It is
the general policy of the Collector
to sell only those gemstones whose
enhancements (if any) have good to excellent stability.
In the event that we offer a gem with
less than good stability, we will ensure
you are aware of the special care needed
for that stone. A gemstone enhancement
is considered stable as long as the
gem does not change in appearance (color
and/or clarity) under normal wear,
cutting, cleaning, repair or display
conditions. Gemstones can be divided
into three basic enhancement categories.
- Not
Enhanced (N)
The “N” symbol is used on our invoices to indicate
one of two situations. First, there are certain gemstones
that are not currently known to be enhanced (alexandrite,
some garnets, etc.). Second, the “N” symbol may
also be used for a gem where it can be proved via gemological
or other means that a gem has not been subjected to any
enhancement. When you see the “N” symbol on
our invoice, we guarantee that the gem in question is
unenhanced.
- Normally
Enhanced (E)
The “E” symbol is used for gemstones
that are routinely enhanced. Since many enhancements
are difficult
or impractical to prove definitively, unless otherwise
indicated, our approach is to assume that such enhancements
have been applied to that particular gemstone. This assumption
is made to protect both buyer and seller. If a more specific
method of enhancement is known, then the specific enhancement
code will be used.
- Nontraditional
Enhancements (T)
For gemstones not covered by the “N” and “E” symbols,
a code covering the specific gemstone enhancement will
be listed.
Symbols
For Specific Forms of Enhancement
- B
= Bleaching: The use of heat, light and/or chemicals
or other agents to lighten or remove a gemstone's
color. This is often accompanied by subsequent dying
and/or impregnation. Example: bleached cultured pearl;
bleached/impregnated jadeite (‘B-jade’)
- C
= Coating: The use of such surface enhancements
as lacquering, enameling, inking, foiling, or sputtering
of films to improve appearance, provide color or
add other special effects. Example: coated diamond
- D
= Dyeing (staining): The introduction of coloring
matter into a gemstone to give it new color, intensify
existing color or improve color uniformity. Example:
dyed green jadeite
- F
= Filling: The filling of surface-breaking cavities
or fissures with colorless glass, plastic, or some
similar substance. This process will improve durability,
appearance and/or add weight. Example: ruby
- Fh
= Flux healing: During heat enhancement, fluxes
(or heat alone) may be used to heal fractures/fissures
which were formerly open. The process dissolves the
walls of the fractures and redeposits the molten
gem material, healing the fractures closed. Example:
ruby (particularly that from Möng Hsu, Burma)
- H
= Heating: The use of heat to alter color, clarity,
and/or phenomena. Example:
Ruby, sapphire, tanzanite, aquamarine, demantoid
garnet
- I
= Impregnation: The impregnation of a porous
gemstone with a colorless agent (usually plastic)
to give it durability and improve appearance. Example:
Stabilized turquoise
- L
= Lasering: The use of a laser and chemicals
to reach and alter inclusions. Example: diamond
- O
= Oiling/Resin Infusion: The filling of surface-breaking
fissures with a colorless oil, wax, resin
or other colorless substances, except glass or plastic,
to improve the gemstone’s appearance. Example:
emerald
- R
= Irradiation: The use of neutrons, gamma, ultraviolet
and/or electron bombardment to alter a gemstone’s
color. The irradiation may be followed by a heating
process
Example: blue topaz
- U
= Lattice (‘bulk’ or ‘surface’)
Diffusion: Outside-in
diffusion of coloring chemicals via high-temperature
heat treatment to produce color and/or asterism. Example:
lattice diffusion-treated sapphire
- W
= Waxing/Oiling: The impregnation of a colorless wax,
paraffin and/or oil in porous gemstones to improve
appearance. Example: jadeite
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