Gemstone Buyers Guide: Treatments and Enhancements
A treatment, or enhancement, is a way of adding beauty to a stone
Most people do not realize that 90+ percent of gemstones on the market these days are enhanced or treated in some way, and thank goodness, otherwise the price would be far out of reach, for most of us!
An official of the American Gem Trade Association said recently that enhancements are prevalent today because "the consumer has developed these unreal expectations of what they want in a gemstone."
Consumer expectations have been fed by a marketplace that offers what seem to be beautiful gems, at lower and lower prices. Usually low priced gems are really lower quality stones that have been treated.
New technologies bring new treatment methods on to the market all of the time, but the following list covers most types of treatments you will see on the market:
• Oiling
• Heating
• Fracture filling
• Beryllium, Treatment
• Leaded Glass Fracture Filling
Emeralds, for example, are routinely oiled to bring out their color. Such treatments do not camouflage flaws or harm the stone in any way. The jewelry retailer need not specifically mention treatments that are regarded as the usual way of dealing with that kind of gem (as described in The Gemstone Enhancement Manual, the jewelry industry's standard reference for gem treatments).
Other treatments are done to stones of lower quality to make them appear more attractive. A trained gemologist, using a microscope can see if a stone has been treated, but often the consumer cannot. If a seller does not disclose such treatments, a customer would believe the gem to be of higher quality than it is and might be led to pay a higher price.
All treatments that are not accepted as part of the normal processing of a gem should always be specifically disclosed, both verbally and on the sales receipt.
Shopping Considerations
• Use caution when you shop on the web. The Federal Trade Commission has discovered a number of online jewelry retailers and auction sites that are not complying with disclosure requirements for colored gemstone treatments (among other things). If a seller does not mention treatments, always ask whether the gem has been treated, especially is the price seems unnaturally low.
Treatments should be disclosed on the sales receipt and on the appraisal, but assume your gem has been treated in some way, unless otherwise indicated. Naturally occurring gemstones that are virtually flawless AND unenhanced/untreated, are so rare that they command a premium. For some types, (for example: Emeralds, Sapphires and Rubies) , the cost per carat may exceed that of a fine quality diamond. Emeralds of that quality are so rare that they could command prices of $30,000.00-$80,000.00 per carat! Rubies and Sapphires that are completely untreated are not far behind, in price!
So thankfully, treatments and enhancements exist to allow more gemstones to be available, and to be affordable.
Here at Alexandria International Group, LLC, we make every effort to price our gems as fairly as possible, and to disclose known treatments. We do not mark up our gems unfairly, as others may do, and we believe that you will be hard pressed to find a better value for your money.
We are dedicated to integrity and make every effort to provide gemstones that do not provide any material support for terrorist groups, or for any ongoing armed conflicts around the world.
Many of our gemstones have Identification Reports issued by the Gemological Institute of America (GIA) http://www.gia.edu/GIAReports/31515/anatomy_of_gia_reports.cfm , long considered on the world’s foremost authority on gemstones and diamonds.
Emeralds
A large flawless emerald is so rare that, carat for carat, it is often worth considerably more than a fine diamond. Emeralds typically range from .04 to 4 carats, although faceted stones of 100 carats and more are known. Their color usually ranges from bluish green to green. Emeralds fall into what is known as “Category III” in the gem industry. That means that eye-visible inclusions or growth characteristics are expected, and are considered to be normal. Emeralds are usually treated with oil and as emerald is not a hard a stone as others, care should be taken.
Emerald Treatments
Oiling is an enhancement routinely done to improve the appearance of emeralds. A colorless oil penetrates into voids and fissures that reach the surface. It does not harm the gem, but temperature changes, chemicals, and ultrasound used in cleaning may affect the stability of the treatment, so care should be taken when cleaning or repairs are made! Enhancements other than oiling should be disclosed, both verbally and on the sales receipt and appraisal.
Treatments that Should Be Disclosed
• Dyed with Colored Oil or Dye- this enhancement is seen occasionally and stabilized cement is done occasionally. Temperature changes, chemicals, and ultrasound may harm the treatment.
• Colorless Bonding Agents- this treatment improves the durability and appearance of the emerald. Avoid temperature changes and chemicals.
• Fracture Filling- as emeralds are apt to have internal cracks or fractures, they are often subjected to fracture filling, which means a fracture in the stone is injected with a foreign substance to make the flaw less visible. The treatment is inexpensive and it can immensely improve the gem's appearance (to the unaided eye). Be aware that this treatment only conceals a weakness that is still present in the stone, and that the treatment may not be permanent. Also be aware that a fracture-filled emerald is not worth as much as an untreated emerald of similar appearance.
Natural Emerald From Afghanistan, Oiled
Shopping Considerations
• As fracture filling of emeralds is becoming so common, ask specifically about this treatment. Fractures that are hidden by a filling can become apparent again should the treatment break down. If you choose to take a chance with a filled stone, at least be sure you are not paying for a high-quality gem.
• Emeralds have a low toughness rating, which means the stones can crack under pressure from a poorly designed mounting. Damage can also result from temperature changes or from improper cleaning by boiling, steam, chemicals or ultrasound.
• Verify that the emerald is natural and not laboratory grown. “Lab created” emeralds, also referred to as “Lab Grown” or “Synthetic” are real emeralds, and chemically identical to their natural counterparts, but they are inexpensive to produce. There are exceptionally good Synthetic emeralds on the market, and they can be difficult to tell apart from an emerald that has grown naturally in the earth.
Beware of Emeralds that look nearly flawless. Synthetic emeralds, while they can be quite beautiful, typically sell for 5% to 10% of the price of a natural gem. If you are paying for a natural gem, be sure that is what you are getting.
Sapphire
Sapphire Treatments
Sapphires are usually heated to intensify color, to make color more uniform, or to darken or lighten stones. Most Sapphire treatments are very stable, normally permanent and requires no special care, however, re-polishing or re-cutting are often not recommended, depending on the type of treatment.
If the sapphire is not heat treated, it should be stated on the sales receipt and any appraisal, as the value of an untreated stone is greater than that of a heated or treated stone of the same appearance.
Treatments other than heating have become widespread and should be specifically disclosed.
 Natural Sapphire, Heated
Treatments That Should Be Disclosed:
• Diffusion- The stone is subjected to chemicals and high temperatures to produce a shallow subsurface layer of color. Diffusion may also create inclusions that produce asterism, an attractive star-like effect. The treatment is permanent and stable, as long as the stone is not re-polished or recut.
• Irradiation- Yellow stones are occasionally irradiated to provide temporary intense yellow or orange color. The effect fades quickly in light or heat.
• Oiling- An increasing number of sapphires treated with oil are appearing in the marketplace. Oiling the stone is a way to fill surface fractures. This treatment enables gem dealers to sell a larger stone (at a higher price) because fractures that might otherwise have to be cut away are filled with oil. Oiling is not permanent and does not affect the stability or structure of the Sapphire.
Shopping Considerations and Caveats
• Sapphires come in many different and wonderful colors- not just blue!
• Be suspicious of very intense yellow or orange sapphires. Ask whether they have been irradiated. This treatment will not last.
• Most naturally-colored yellow or gold sapphires available on the market have been enhanced by a treatment known as beryllium diffusion- a permanent, stable treatment, widely accepted as normal in the market.
• Ask whether the stone has been oiled. This treatment is coming into use and is often not disclosed by the gem supplier. Unless your jewelry retailer is a trained gemologist, or if the stone has not been sent to a gem laboratory for identification, he or she may not be aware that a stone has been oil treated.
• Insist that all treatments be stated on the sales receipt and on any appraisals.
• Today it is quite unusual to find some types of gems untreated--an untreated sapphire from Ceylon or Kashmir, for example. If a stone is completely untreated, then that should also appear on the appraisal, as such a stone is worth much, much more than a treated stone of the same appearance.
• Other gemstones, such as Beryl, Spinel and Topaz can be colored to look similar to dark blue sapphire and they are sometimes passed off as such. Ask for verification in writing that what you are buying is natural sapphire.
• Verify that the stone is natural rather than “Lab Created” also called “Synthetic” Sapphire. A Synthetic Sapphire will have the same chemical properties as a natural Sapphire, and are often beautiful, but the cost of a Synthetic Sapphire should be less than the cost of natural Sapphire
• Many of our Sapphires come with a gem Identification Report from the Gemological Institute of America (GIA) or other reputable gem identification lab. With or without a certificate, at Alexandria International Group, LLC, we take great pride in our commitment to disclosure and fair pricing.
Ruby
Ruby Treatments
Rubies are usually heated to improve their color and appearance. The enhancement is quite stable and no special care is needed with the stone.
Other treatments are common practice in dealing with rubies and they should be specifically disclosed.
Treatments That Should Be Disclosed:
• Surface Cavities Filled- a foreign material, such as glass, is used to fill surface fractures. The danger is that the foreign material will simply fall out.
• Dyed with Colored Oil- oiling is a way to fill surface fractures as well as enhance the gem's color. It used to be a rare practice but is becoming quite widespread as a way to make low quality rubies more attractive. Oil fillers are less stable than glass used as fillers. The oils evaporate over time, leaving an unattractive stone with very visible fractures.
• Diffusion- the ruby is subjected to chemicals and high temperatures to produce a shallow subsurface layer of color. Diffusion may also create inclusions that produce asterism, an attractive star-like effect. The treatment's stability is good if the stone is not repolished or recut.
• Fracture Filling with Leaded Glass or other material: It has become increasing common to see natural ruby that is fracture filled with leaded glass. Fracture filling with leaded glass is considered to be a stable treatment and permanent, although the treatment may make structural weakness within a stone harder to detect.
This process usually consists of lower quality Ruby being heated to a high temperature, to improve the color, with components of leaded glass added during the heating process. The components melt to fill any surface-reaching fractures, and the end result is a ruby that appears to be of much higher quality. Rubies fracture filled in this manner are often difficult to distinguish, even for a well trained gemologist. Rubies fracture filled are currently valued far below other types of enhancements or treatments, but this allows more people to experience the job of owning and wearing a natural ruby, at an affordable price.
Natural Ruby, fracture-filled with leaded glass
Flux Filling This process usually consists of lower quality Ruby being heated to a high temperature, to improve the color, with components of borax and sometimes other components added during the heating process. The components melt to fill any surface-reaching fractures, and dries clear. The end result is a ruby that appears to be of much higher quality. Rubies fracture filled in this manner are often difficult to distinguish, even for a well trained gemologist. Rubies fracture filled are currently valued far below other types of enhancements or treatments, but this allows more people to experience the job of owning and wearing a natural ruby, at an affordable price.
Shopping Considerations
• Ask whether or not the ruby has been treated. All enhancements except heating should be disclosed on the sales receipt and on the appraisal. If the ruby is unheated, that should be stated on the receipt, as unheated ruby is considerably more valuable than one that is heated.
• Ultrasonic cleaning or chemicals can damage rubies.
• Laboratory Grown, often referred to as “Synthetic” rubies are widely available. When comparison shopping, be sure to ask whether the ruby is natural or synthetic. Synthetic gems have a far lower value.
Many of our Rubies come with a gem Identification Report from the Gemological Institute of America (GIA) or other reputable gem identification lab. With or without a certificate, at Alexandria International Group, LLC, we take great prides in our commitment to disclosure and fair pricing. You can rest assured that what you are purchasing is what you will receive.
Most gem treatments are undetectable by the naked eye and treatments and enhancements can often be difficult to detect, even for a trained gemologist.
Natural untreated or unenhanced gemstones command a premium, as they have become so rare. 90%+ of the gemstones available on the market today are treated or enhanced in some way, so as to enhance their visual appeal.
Alexandria International Group, LLC, offers a 30 day, money-back guarantee- we want you to be delighted with any gem your receive from us!
GIA CLARITY GRADING USED BY ALEXANDRIA INTERNATIONAL GROUP, LLC
Different gem labs grade clarity in colored gemstones differently. Alexandria International Group, LLC, uses the newest GIA (Gemological Institute of America) Colored Gemstone Grading Scale.
According to the GIA – perhaps the world’s best known and trusted Gem Association and Lab, there are THREE different charts for grading colored gemstones (the Diamonds chart is a separate grading scale). Perhaps the one that most jewelers are familiar with is the GIA Clarity Chart for grading Diamonds, and it is common to see (esp on E-bay), colored stones graded incorrectly, often using an outdated diamond grading scale.
The following information is the most recent and most accurate grading scale used by the GIA:
Type I Gemstones are usually
eye-clean with no inclusions visible to the unaided eye. The stones in
this type are usually of such high clarity that even minor inclusions
can detract from their desirability.
Category Type I Gemstones: Aquamarine, Pink/Green/Yellow Beryl, All Chrysoberyl (excluding Alexandrite), Spodumene, Blue Topaz, Green Tourmaline, Blue & Volorless Zircon, Zosite.
Type II Gemstones typically show some eye-visible inclusions that don't detract from the gems's overall beauty. Manystones with inclusions visible to the unaided eye are faceted for use in jewelry.
Category Type II Gemstones: Andalusite, Apatite, Alexandrite, Corundum (Sapphire and Ruby), Diopside, Feldspar, Garnet, Iolite, Fire Opal, Peridot, Quartz (including Amethyst, Citrine, Ametrine), Spinel, MOst colors of Tourmaline (except green & Watermelon) Zircon (except blue and colorless).
Type III Gemstones are almost always included and show eye-visible inclusions, but even specimens with obvious or prominent inclusions are often for use in jewelry.
Category Type III Gemstones: Emerald, Red Beryl, Watermelon Tourmaline.
Gemstone Enhancement Codes
Gemstone Saturation Chart & Gemstone Tone Chart
The
GIA nomenclature also specifies six levels of saturation ranging from
"grayish" (neutral grey) to "moderately strong" to "vivid." The term
"intensity" is also used to describe a stone's saturation.
To describe the darkness or lightness of a colored stone, the GIA system has nine levels of tone ranging from "very very light" to "very very dark." A numerical value is assigned to each label for use in a grading report.
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