Diamonds attract money. Like anything else that attracts money, diamonds attract scammers. Here is a list of scams to beware of when buying or trading diamonds.
HIDING FLAWS: The most common way a jeweler tries to hide flaws is to put the flaw under the prongs of the setting. Many times the seller tries to make it difficult to inspect the diamond bare. That makes it all the more important for the buyer to try to view all parts of the gem. Certain structural flaws like feathers and cleavages are exacerbated by high pressure bindings of the prongs, so this is a very suspicious area.
BLUE-WHITE: A jeweler who tries to convince a buyer that blue is the preferred color for diamonds is misleading the buyer. Under some circumstances in natural light some diamonds can take on a bluish tinge. But that is an exception, not the rule. Blueness should be minimum, if not absent entirely. Look at the piece under blue flouresent light. If this kind of light makes the diamond murky looking, the diamond is inferior.
INTENSE LIGHT: Bright lights make any natural diamond look better. A jeweler prefers to show her or his merchandise in strong light, with or without specialized lighting tricks. For this reason it is important to view any stones under a wide variety of lighting conditions, not just under the glare of showroom lights.
GRADE INFLATION: ‘Grade Inflation’ describes how teachers increase the grades of students to win their praise and/or silence. The same kind of inflation is done by diamond merchants to increase prices artificially. Unfortunately there is a subjective element in assigning grades to diamonds. Given this subjective element, it is inevitable that some people will be tempted to cheat. There can be a significant price difference between grades, especially for larger gems. There are laboratories to which gems can be sent for additional evaluations. If it is possible to do so, get a second opinion.
SIZE MATTERS: Diamonds are usually small. That means that the difference in price between size measurement units can be significant, since prices can leap for certain popular sizes. A diamond that is .69 carats, for example, should sell for about the same price as a diamond of .80 carats, according to prevailing conventions. But not every seller follows these rules, so small differences are sometimes exaggerated to increase prices artificially.
LASER DRILLING: Many — perhaps as many as a third — diamonds have small carbon spots. Dealers drill holes with lasers to burn out these spots. Not only is this a form of artificial enhancement, but laser drilling can make the diamond more fragile. A strong bump can splinter a lasered gem. Laser-drilled diamonds should sell for less than more pristine pieces.
FILLING FRACTURES: There are treatments which make flaws less visible or actually invisible to a non-expert. But this treatment does not survive the high heat when the diamond is set into a ring. Diamonds whose fractures have been filled should sell for much less. But since they can look good under many circumstances, they pass some tests and get higher prices.
PAINTED WOMAN: A little drop of paint at the very lowest tip of the diamond (called a culet) can go a long way to deceive. The paint spot adds just enough color to hide flaws of some types. But it does not survive very long. Perhaps only as long as it takes for the deceived buyer to take the item home. diamond painting