# Gemstone Treatment (Enhancement): Any human controlled process other than cutting
and polishing that improves the appearance (color/clarity/phenomena), durability or value of a
gemstone.*Many in the trade call them “Enhancements” But the US Federal Trade Commission(FTC)-as
well as many gem professionals considers “treatment” the more accurate term.
# Gems are treated for a number of different reasons:
*Remove,change or deepen color: Tanzanite.
*Improve clarity: Emerald.
*Create phenomena & desirable inclusions: Amber & stars.
*Improve luster: Jadeit.
*Improve durability: Turquoise.
Treatment (Enhancement) codes.
N : Natural (No treatments) ASBL:Assemble -Material made up more than one material. Some or all components
can be natural but still boned together.Doublet or Triplet. Doublet: Two separate pieces
of material fused or cemented together to form a single assembled stone.Triplet: A
single assembled stone made from three separate pieces of material fused or cemented
together. B : Bleaching -Uses chemicals to lighten or remove color. C :Coating/ surface modification - Surface modification as lacquering,
backing,coloring or sputtering of films to improve appearance, provide color or add other
special effects. CMP :Composite -Material made from two or more constituent materials with
significantly different physical or chemical properties. or layers assembled by
bonding or other artificial methods. D : Dyeing -Adds color or affects color by deepening it,making it more
even,or improve color uniformity. F : Fracture(often called fissure) filling -Using a filler (colorless oils,
glass,plastic, resins, polymers,hardener, solidified borax or similar
substances) to conceal fractures and improve the apparent clarity of a gem. GF : Glass filled -Glass filled or composite ruby or sapphire: fractures filled with
high-lead-content glass, which made them appear very transparent. Performed at lower
temperatures, this is a less durable treatment and should be treated gently, avoiding
household and professional chemicals. H : Heat Treatment -Exposing a gem to rising temperatures for the purpose of
changing its appearance. This is an old process, and 95% of corundum, all tanzanite,
zircon,aquamarine and amber are often heated.Heat treatment are generally stable. HP : Heating & pressure -The use of temperature and pressure combined to effect
desired alteration of color, clarity and/or phenomena. Hydro:Hydrothermal Growth - A process in which nutrients(natural quartz seed
crystals) dissolve in a water solution and chemicals at high temperature and pressure,
cool to form synthetic crystals.the first hydrothermal quartz appeared in laboratories in
the 1890s.hydrothermal synthetic Emerald for jewelry came on the 1960s. I :Impregnation -Filling of a porou gemstone or other openings with melted wax, resins,
polymer, or plastic to improve appearance and stability. Some dealers called
stabilization as well. L : Lasering - A clarity treatment that using a concentrated beam of laser
light to reach a gemstone’s dark inclusions and disguise or eliminate them. Usually
diamond. O: Oilong/ Resin -The filling of surface-breaking fissures with colorless oil, wax & resin. R: Irradiation -Exposing a gem to electromagnetic radiation X-rays or gamma rays or
subatomic particles ( neutrons or electrons ) to change gemstone’s color. The color
centers aren’t always permanent. In some cases, heat or light can destroy them and
remove the color.Irradiated blue topaz made a big impact on the market in the 1980s. SIM: Simulated - Any gemstone a wide variety of less expensive look alike
same materials. Some of them come from the ground and some from the
lab.the imitations are called simulated and is used in its place. SYN: Synthetic gem -Made in laboratories, but they have essentially the
same chemical composition, crystal structure, and properties as their natural
counterpart. SC : Special care - Avoid chemicals, heat, light, and don’t use ultrasonic
cleaner or steamer. Clean with warm soapy water and soft brush or cloth. U : Lattice Diffusion/Diffusion -Experimentation during the 1980s,Lattice
diffusion treatment is applied to colorless or very light colored natural
corundum, especially sapphire that doesn’t respond to normal heat
treatment.Treaters place faceted corundum in a crucible containing a
coloring agent like titanium or chromium.Temperature approaching 3700°F
(2050°c) melting point of corundum with iron and titanium oxides to create
blue stones and with chromium to create red stones. Beryllium diffusion is
newer corundum treatment that result in a wide range of colors. Including
pinkish orange(padparadscha),orange,yellow,red, and blue. W : Waxing/oiling in opaque stones -Wax and oil in porous opaque or
translucent gemstones to improve appearance. Sugar & smoke Treatment-There are two different treatments that darken
opals and bring out their play-of-color, called sugar and smoke treatment. Smoke:Heating a wrapped opal until smoke or ash penetrates its surface to darken it and bring out its play-of-color. Sugar :Soaking an opal in a hot sugar solution and then sulfuric acid to
darken it and bring out its play-of-color.
Gemstone Enhancement Codes*
N = Not Enhanced, B = Bleaching, C = Coating, D = Dyeing, F = Filling, H =
Heating, HP = Heat & Pressure, I = Impregnation, L = Lasering, O =
Oiling/Resin, R = Irradiation, U = Diffusion, SC = Special Care, ASBL =
Assembled, CMP = Composite, W = Waxing/Oiling in Opaque Stones
*Codes and type of treatments must only be used as directed in the
Gemstone Information Manual, available at www.agta.org and www.gia.edu.