Tricks of the Trade


Some jewelers may try to market a “blue-white” diamond as though it were a white diamond with a hint of blue, and more valuable than a plain white diamond. It’s not! It’s a diamond that fluoresces blue and is therefore less valuable. Avoid it!


Browsing through your Sunday paper you spot an exciting ad: a local jeweler is having a “50% Off” sale on diamonds! Wow! You jump into your car, drive to the store, and you make what you are sure is an incredible buy on a one-carat diamond.You’re still patting yourself on the back a week later when you happen to walk past another jewelry store where you see the same size, same quality diamond selling for less than what you paid and it’s their regular price! What happened?

You were taken in by a fake sale. Many jewelers run these sales. They’ll take a diamond that is worth, say, $1,000 wholesale and instead of marking it up 100%, which is standard practice, they mark it up 400% and tell you that $4,000 is the regular price when in fact the regular price for such a stone would be $2,000. Then the jeweler takes 50% off the inflated price and sells it to you for full retail, $2,000.

The way to know if you’re really getting a sale price is to compare the jeweler’s price with the wholesale price list in the book. If the jeweler’s regular price is more than double the wholesale price, you’re not getting any bargain.

For example: Joe’s Jewelry Store has a one-carat VS1-G on sale for $12,400, marked down from $24,800. You look at my price list and see that a one-carat VS1-G wholesales for $6,200. Therefore, full retail should be $12,400. Joe has artificially inflated the “regular” price to trick you into believing you’re getting a bargain.


This is a term that’s been around for a long time, and it’s not limited to the diamond business. Bait and switch refers to anyone who runs an advertising special on a particular item just to get you into the store. When you go to the store, however, you’re told that the advertised item is sold out. Then they try to sell you something else – invariably, something more expensive. The jeweler hopes that since you’ve already made the trip to the store, you won’t want to go home empty-handed.

Don’t be impatient! Many people arrive at the store determined to buy something and get talked into something they don’t really want. Take control! Grade the jeweler using the Jeweler Questionnaire Sheet in my book, and if he or she passes the test, stick around and look at some diamonds, using a scratch sheet to check each one. Compare the prices to the wholesale prices in the book to see what kind of deal you’re being offered, and for an exact updated price on a particular stone, call my HelpLine.


Jewelers love diamonds that fluoresce blue, and will sometimes install special lighting to enhance the fluorescence of their diamonds. The blue masks the yellow color that might be in the diamond and makes it appear to be a higher color grade than it really is. Always take the loose diamond you’re looking at and place it on a white background to check the color, and make sure there are no spotlights shining on it. Always take the loose diamond you’re looking at and place it on a white background to check the color, and make sure there are no spotlights shining on it.


The Federal Trade Commission requires that a diamond be within one clarity and one color grade of what it is originally sold as. Because of this, jewelers tend to “bump” the grade. For example, if a jeweler buys a stone as a VS1-G, he’ll bump it up and sell it as a VVS2-F. If you buy it as a VVS2-F and have it appraised as a VS1-G, the dealer is legally covered, because he sold it within one grade of what it really is.


Some jewelers will list the weights of their diamonds only in fractions, such as 3/4 of a carat. Your next question should be, “Well, is it 75 points are not?” Many jewelers will call anything from 65 to 75 points a 3/4 carat diamond. These same jewelers will call anything from 90 points to 100 points a full carat. This is illegal. A diamond must weigh within half a point of its stated weight. You’ll notice a jeweler will never round a diamond down they’d never call an 85-pointer a 3/4 carat stone. Ask the jeweler to weigh the stone, in front of you, on an electronic scale. If he says he can’t because it’s in a setting, you shouldn’t be looking at it anyway. Only buy loose diamonds.


You’ve shopped around, rated the jewelers, graded the diamonds, and finally found the stone you want. You lay your money down and order a setting. When you get the ring, you have it independently appraised – only to discover that the diamond in the ring isn’t the same stone you purchased! The jeweler has pulled a switcheroo. You go back and confront him, and he accuses you of switching stones. What now?

Well, sad to say, you’re stuck. There’s really nothing you can do, no way to prove a switch was made. You must prevent the switcheroo before it happens.

When you decide on a diamond, get the jeweler to put in writing the exact weight, and the clarity and color grades of the stone. Before he diamond is mounted, have the jeweler show you where the blemishes and inclusions are, and plot them on a drawing. Keep this drawing with you, and when you return to pick up the mounted diamond, check it again, looking for the same flaws that are on your drawing. If they match, you have the right diamond.


If you’ve purchased a diamond by following all my instructions, you shouldn’t feel the need to go to an independent appraiser to double-check your purchase. But if you do, watch out for the sandbagger! The sandbagger is someone who lies to you and tells you that you’ve been taken, that your diamond isn’t worth what you paid for it. Why would he do that? So that he can recommend where you should buy your diamonds – no doubt at a place which gives him a kickback! Or he may tell you, “You should have bought from me.”

Fred’s Advice: If you ever want to have the diamond checked, don’t take a chance. Send it to GIA for an unbiased opinion.


Now you see it – now you don’t! Carbon, that is. There is a laser beam process for removing carbon from inside a diamond. It’s called laser drilling. A diamond that contains black carbon, visible with a 10X loupe, is zapped with a fine laser beam which vaporizes the carbon, removing the black spot.The problem is that the laser beam creates a tunnel from the surface of the diamond to where the carbon used to be. You might not be able to see this tunnel with the naked eye, but you’ll see it under a loupe. And if a stone has been drilled several times, it can be weakened.

Laser drilling can make a diamond more attractive to the eye, but it can also lower the resale value. Beware! The Federal Trade Commission no longer requires jewelers to disclose to consumers whether a diamond has been laser drilled.

by Fred Cuellar, author of the best-selling book “How to Buy a Diamond.” More questions? Ask the Diamond Guy®
The founder and president of Diamond Cutters International, Fred Cuellar is one of the top diamond experts in the world, as well as a three-time Guinness Book record holder in jewelry design.
Fred Cuellar
Latest posts by Fred Cuellar (see all)

This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish.

A few steps for you to expect once you submit your form - We will first send you an email confirming that we’ve received your form, so keep an eye out for that.  We will then contact you within 24 hours via your preferred method of contact. We will work with you to setup a complimentary one-on-one consultation with your gemologist.