1 What is the best way to find a competent jeweler?

2 Is my jewelry automatically insured while being repaired or appraised?

3 How often should my jewelry be cleaned, and by what method?

4 How often should I have the prongs on my engagement ring checked?

5 How often should pearls and beads be re-strung?

6 How is a ring sized?

7 Can a ring be stretched or shrunk?

8 Is costume jewelry repairable?

9 What is laser welding?

10 How often should my watch be cleaned?

11 Who is the best person to repair my watch?

12 What does "water resistance" mean?

13 How do I get my watch to be water-resistant?

14 What is the difference between water resistant and waterproof?

Appraisals and Gemology

16 How can I be sure I am receiving a proper appraisal?

17 How is the appraised value determined?

18 How can I find out the value of my jewelry without getting an appraisal?

19 How do I know if my gemstones are genuine?

20 How do I know if my pearls are cultured, natural, or simulated?

21 How do I know if my item of "antique" jewelry is authentic or a reproduction?

22 What is the nature of the new diamond simulant, synthetic moissanite, and how does it differ from cubic zirconia?

23 What does "fracture filled" mean and does it affect the value of my gemstone?

24 What does a jeweler have to disclose about merchandise offered for sale?
 
 

First of all, the word "genuine" means different things to different people, and changes according to the situation. Generally gemstones are divided into three categories:

• Natural 

For example, a ruby that comes out of the ground and is faceted and polished in preparation for sale (or simply left in its rough form) is considered natural. 
• Laboratory grown (aka synthetic) 

Rubies are also grown in laboratories, often employing methods that closely simulate the natural process that occurs when rubies form in the earth. Chemically, optically, and structurally, these laboratory-grown gems very closely resemble their natural counterpart. 
• Simulated. 

Additionally, red glass or other materials that bear no gemological or chemical resemblance to ruby can be used to simulate ruby. 

Most gems are readily identified with standard gemological testing. Those that prove more challenging can be submitted to highly sophisticated gemological laboratories for identification and in many cases, determination of the country of origin. Country of origin can be a significant value factor in certain categories, such as Burmese ruby, Kashmir sapphire, and Colombian emerald.

First of all, let's distinguish between the three. Natural pearls are just as the words indicate. These pearls form naturally when an irritant such as a grain of sand enters the mollusk, which secretes "nacre" (pronounced nay-ker) to protect itself from the foreign matter. The nacre forms what is eventually a pearl.

Cultured pearls are formed in much the same way, but the irritant, or "nucleus," is implanted in the mollusk by human beings, which then harvest the pearls at varying levels of maturity. The size of the pearl is determined by both the size of the nucleus and the time allowed for the nacre to grow thicker around that nucleus.

A simulated pearl is any material that is meant to look like a cultured or natural pearl. Such simulants usually consist of a plastic or glass bead coated with a pearl-like skin. The Federal Trade Commission Guidelines for the Jewelry Industry address disclosure and terminology issues with regard to pearls.

There are ways in which to examine pearls gemologically in order to determine their identity as natural, cultured, or simulated. However, a reasonably reliable test can be performed by the untrained consumer. If you have pearls in your possession, carefully run one or more across the edge of one of your front teeth. If the surface feels slightly grainy, like very fine sandpaper, you have confirmed that the pearl is cultured or natural. Any simulant will feel absolutely smooth as you run it across the edge of your tooth. If you are still in doubt, consult with a qualified jeweler or gemologist.

Differentiating between authentic antique (defined by U.S. Customs as 100 years or more in age) or period jewelry and modern reproductions is a skill that is developed only through extensive experience and research. There are various clues that indicate an item's age, and with time the student of antique and period jewelry learns to recognize many of these signs. For example, a certain kind of mechanical safety catch replaced the simple wire "C catch" around 1896 in Europe, and a few years later here in the United States. If the observer can be sure after thorough examination that a safety catch is original to the piece, and it is mechanical, the age of the item can be estimated within a very few year period. Other characteristics such as the delicacy or heaviness of the piece, the quality of workmanship, the cutting style of diamonds or other gemstones and the manner in which they are set, and hallmarks and date letters, all provide clues as to an item's age and perhaps country of origin as well.
 

Until recently cubic zirconia ("CZ") was considered the most effective imitator of diamond readily available to the public. CZ should rightfully be called "synthetic" or "laboratory grown" cubic zirconia, because the material commercially available is manufactured in laboratories, rather than found in the earth. In nature, cubic zirconia, actually zirconium oxide, generally appears as the mineralbaddeleyite, and is not commercially viable. 

Manufactured CZ is considerably heavier than diamond, having a specific gravity of approximately 5.8 (meaning that its weight is 5.8 times that of water in equal volume, as opposed to diamond's 3.52). CZ has a hardness of 8.5 on the Mohs Scale, as opposed to diamond's 10. 

Recently synthetic moissanite (silicon carbide, or "carborundum") has appeared on the market and is convincing as a diamond simulant in one especially significant way that CZ is not. Moissanite is troublesome to someone who is not prepared for its presence because it reacts positively to conventional thermal testers that beep when touched to diamond and are silent when applied to any other gem material. Essentially, moissanite thereby "fools" the diamond tester. However, there are several ways to recognize synthetic moissanite, and a competent gemologist should have no trouble distinguishing between it and diamond. It is important to note, however, that synthetic moissanite has a hardness of 9.5, exceeding that of even sapphire and ruby which rate a hardness of 9.

Among other characteristics, synthetic moissanite is exhibits double refraction, that is, it has the quality of separating a single ray of light into two. Diamond is singly refractive. Gemologists can readily identify double refraction in moissanite in the form of "doubling" of facet junctions visible at certain angles with a jeweler's 10 power loupe. This is one simple visual test, and several others too lengthy and technical to describe here, are also at the disposal of the properly prepared gemologist.

Fracture filling, sometimes known as 
"clarity enhancement," is a process whereby any surface-reaching fissure in a gemstone can be filled in order to enhance the gemstone's beauty, durability, or both.

It is important to note that gemstones have been treated in a variety of ways for hundreds and in some cases, thousands of years. Emeralds were oiled to enhance their beauty as long ago as the days of Cleopatra, if not before! Enhancing techniques in and of themselves are not necessarily detrimental or unethical. Failure to disclose their presence, however, is another matter.

Oiling of emeralds has continued to this day. However, modern technology has allowed producers to go further in the enhancement of emeralds as well as many other gemstones. Various substances such as polymers (colorless or dyed) are now being applied to a variety of materials. Treatments in many cases benefit the consumer, as in the case of polymers that strengthen emeralds while enhancing their beauty. One such filling material, known as the Gematrat® treatment, is so stable that it allows treated emeralds to be ultrasonically cleaned. Oiled emeralds cannot be cleaned ultrasonically because the cleaning action damages or removes the oil and negatively affects the appearance of the emerald. Stable or not, polymer or oil, dyed or not dyed, any and all of these treatments must be disclosed to consumers by the seller.

Fracture-filling in diamonds is a process invented during the 1980's, and involves the infusion under high heat and pressure of a compound that fills surface reaching fissures, thereby making them less visible. An experienced gemologist will detect the filler in the form of bright blue and/or orange flashes visible under magnification under proper lighting, viewed at a particular angle to the filled fissure. Various studies of the filler material seems to indicate that it may change color with age. Also, the filler will be melted or burned by the torch heat required to effect certain repairs such as prong re-tipping.

On the positive side, fracture filling dramatically improves the appearance of otherwise unattractive diamonds, and allows consumers with a limited budget to purchase a great deal more "look" than they might otherwise be able to afford.

Disclosure of compounds used to fracture-fill diamonds and other gemstones should include information about the care required to ensure the maximum life span of the filler material.

This is perhaps the most far reaching question among all of those posed here on our website. Disclosure issues are probably most pronounced with regard to gemstone enhancements-those processes applied to gemstones in order to enhance their appearance, durability, or both. Disclosure is also critical in the antique and period jewelry arena. If a Victorian brooch has been fitted with a modern safety catch, for example, its desirability to collectors and its value are diminished. Perhaps an antique cut diamond has been replaced with a modern diamond that does not match those others remaining in the piece. This also should be pointed out to a potential buyer.

Back to gemstones for a moment: It is important to know that the Federal Trade Commission's Guidelines for the Jewelry Industry has established clearly stated rules for the jeweler, specifically regarding disclosure and the use of proper terminology. Some forms of disclosure may not be required by the FTC. One example is the diamond that has been drilled with a laser beam and treated to remove internal discoloration. The fact that the Guidelines do not require disclosure does not necessarily mean that the jeweler is not ethically and morally obligated to disclose the existence of the laser drill holes. Wouldn't YOU want to know? The consumer can only make an informed buying decision if the consumer is informed! At the time of this writing the FTC is reconsidering the issue of laser drilling and its disclosure.

Other issues are not so clearly defined. For example, most blue sapphires are heat treated to enhance their color, clarity, or both. Because this form of enhancement is common and widely known and accepted in the jewelry industry, and also because the heat treatment is permanent and stable, it is often ignored during the sales presentation. This is not necessarily meant to deceive the buyer; it is often an honest oversight by the jeweler.

For a copy of the complete Guidelines for the Jewelry Industry contact the Federal Trade Commission in Washington, D.C.