Buying a Diamond? Buyer Beware!

For the most part, jewelers are honest, but there are a few tricks and pitfalls you should be aware of. After all, jewelers are salesmen and they aren’t going to volunteer any information that might jeopardize the sale unless you ask. So we’ve researched a number of diamond selling tactics you need to watch out for. Caveat Emptor! 

The One Carat Weight Ring

This one can cost you some money if you’re unaware of the difference between a couple of industry terms: “total carat weight” (CTW) and “carat weight” (CW or CT). The “total carat weight”, commonly known as CTW, is the sum of the carats in the center stone and all the side stones of the ring added together, while CW is the carat weight of the center stone only.

The reason this is important is that diamonds are priced by their availability. Tiny “Pave” diamonds are readily available and so they are quite inexpensive. For example, a 1/2 carat weight worth of Pave diamonds will be under $200, while a 1/2 carat diamond of the same quality will be over $1000 and a 1 carat diamond of the same quality will cost around $5000.

So, for this example, a 1 CTW Pave Diamond Ring (1/2 carat center stone plus 1/2 carat Pave diamonds) will have about $1200 worth of diamonds, while a 1 CW Diamond Solitaire Ring will cost over $5000. (On a side note, this also helps to explain the popularity of Pave rings, you can get a lot of Bling, for less cost.)

Many jewelers will opt to advertise the CTW because this amount is always more impressive than the amount of the center stone. So if the jeweler says the Ring is “One Carat”, make sure you know whether it’s CTW or CT. There’s a big difference in price!

The Bright Blue Light

Just when a consumer thinks they know how to spot a low-grade diamond, a blue light gets shined on the subject.

Not surprisingly, jewelry stores want to make their diamonds look as good as possible. Sometimes they want to make them look a little too good. Here’s how this one works. Most diamonds will have some degree of yellow tint to them. Since the complementary color to yellow is blue, shining a blue light on a yellow tinted diamond will tend to cancel out the yellow color and make the diamond appear white (clear).

So when at the jewelry store you’ll probably notice that the display cases and inspection lights will have a bluish tint to them. Furthermore, see if the diamond is displayed on black velvet. Black backgrounds can make a yellowish colored diamond look whiter.

The solution is to examine the diamond in sunlight, with a sheet of white paper as the background. Another simple solution is to look at the color rating on the diamond’s GIA certificate.

On a related note, another thing to look out for is Fluorescence.

Typically, around 1/3 of all diamonds exhibit a property called fluorescence when an ultraviolet light is shone on them. The most usual fluorescence color is blue, which again will make the diamonds appear whiter. So when at the jewelry store, watch out for any light source that may have an ultraviolet component to it. What to do: The solution is simple, your GIA Lab report will always mention any fluorescence.

In the bad old days, some unscrupulous jewelers might call a fluorescent diamond a “Blue White” diamond and try to convince you that it’s more valuable. These days the Federal Trade Commission has set very strict limits on a jewelers legal right to use this term.

Fractional Carat Weight

The Federal Trade Commission, by law, allows jewelers to round off diamond carat weights. For example, a diamond labeled as a 1/2 carat diamond could actually weigh as little as .47 carats. Now the difference between a 0.47 carat diamond and a 0.5 carat diamond can be as much as several hundred dollars, so if you’re not paying attention this can cost you some money. See Fractional Carat Weight

Solution: The GIA certificate will give you get an exact weight of the diamond.

The Grade Bumping Loophole

The Federal Trade Commission allows jewelers a margin of error of one color grade and one clarity grade for a diamond. Of course give someone an inch and they’ll take a mile. For example, grading a one carat H colored, SI1 clarity diamond as a G VS2 diamond can be a difference of almost $2000.

The solution is to insist on a current certificate from a non biased diamond lab such as the Gemological Institute of America (GIA), or the American Gem Society (AGS).

The Phony Certificate

You’ve done what you’re supposed to do and demand to see the certificate for the diamond. Voila! The jeweler produces said certificate and all is good. Unfortunately, you forgot to look at the fine print.

That certificate you thought was from the Gemological Institute of America (GIA), is actually from the “Gemological Institutions of America”. Oops! You just got taken.

Another more blatant trick is the “tampered certificate”, in which the unscrupulous jeweler changes the diamond’s grade on the certificate (Like a kid trying to change an “F” to an “A” on their report card). This isn’t easy to do because GIA certificates are laminated. So make sure to look at the lamination on the certificate. All certificates should have a laminated cover. Inspect the corners and edges of the lamination to detect any tampering.

Treated Diamonds 

Treated diamonds are diamonds which have various flaws in clarity or color, which are corrected using a variety of treatments such as: Laser Drilling, Fracture Filling, Irradiation and Chemical Color Coatings.

In general, treated diamonds should cost significantly less than their untreated counterparts. Rarely however, and in violation of FTC regulations, some unscrupulous dealers may attempt to pass off a treated diamond as if it was an untreated diamond of high-quality clarity and color, charging you thousands more than the diamond is worth.

Solution: A GIA Lab report will list any treatments.

The Switcheroo

Suppose you leave your diamond with an unscrupulous jeweler for a setting, resizing, repair or cleaning. The unscrupulous jeweler then switches your diamond for a similar-looking diamond of lesser quality. If you’re not paying attention, you won’t even notice what just happened.

What to do: Make sure you have a GIA certificate for the diamond you purchased and verify with a 10X loupe that the diamond matches the certificate. Another option is to have your diamond laser engraved with your certificate number.

The Nonrefundable Deposit

This is an old trick that has been used by unscrupulous merchants for ages.

In the jewelry variation, the unscrupulous jeweler lets you leave a “deposit” while you take the diamond for an appraisal. Later after you find out the diamond isn’t all that valuable and you want your deposit back, you are told that the deposit isn’t refundable and is only good for a store credit towards another diamond.

What to do: Read the fine print and be prepared to walk out of the store.

The 50% OFF Sale

Another old sales tactic, again not exclusive to jewelry, is the “Big Sale”.

Just remember, the bottom line is that no jewelry store is never desperate enough to give away diamonds. It is not as if diamonds will go out of fashion like bell bottoms. What to do: If anyone offers you a diamond at 50% off, Run!

The Ol’ Bait & Switch

“Sorry, you just missed it,” proclaims the jewelry store clerk. “However, we have these other lovely rings for sale.”

How it works: A diamond store advertises a once in a lifetime sale on a diamond. However, the diamond is sold by the time everyone gets to the store.

What to do: Take your business elsewhere.

You’re looking for an engagement ring, and you want a fair deal and a fair price. One option that is now available is to buy your diamond from a reputable online store that deals only in GIA certified diamonds, and has a good return policy.


All That Glitters… How to Buy Jewelry – Federal Trade Commission