Common Diamond Buying Mistakes

Often, a customer will shop for a diamond using a traditional jeweller, even if they eventually purchase online. The buyer is able to see various diamond sizes, shapes, and qualities first hand; allowing for a more informed and confident online purchase. In some cases, the customer may decide to purchase from the traditional jeweller based on their service and selection. In either case, when shopping for a diamond at a traditional jeweller, keep the following in mind:

Common Diamond Shapes

Round Cut Diamond


Round cut diamonds maximize light return and sparkle, and are the most brilliant of the diamond cuts.


Radiant Cut Diamond


Radiant cut diamonds combine the stylish square or rectangular shape with the brilliance of the round cut.


Pear Cut Diamond


Tradition and brilliance are combined in pear shaped diamonds, creating a diamond which makes light 'dance.'


Emerald Cut Diamond


A stunningly beautiful diamond cut with long lines that give the diamond an elegant and sophisticated look.


Marquise Cut Diamond


The Marquise cut diamond is a boat-shaped brilliant diamond, considered to be a "classic" choice for engagement rings.


Heart Cut Diamond


The ultimate symbol of love, the heart shaped diamond is among the most romantic of the diamond shapes.


Oval Cut Diamond


Oval cut diamonds serve to elegantly elongate fingers, creating the optical illusion of length.


Princess Cut Diamond


The second most popular of the diamond shapes, the princess cut is designed for maximum brilliance.


Cushion Cut Diamond


The cushion cut resembles a pillow and has an antique feel and a distinctive, romantic appearance.


Asscher Cut Diamond


Bright, shiny and extremely clear in appearance, asscher cut diamonds allow you to see right through the diamond.


Select Diamond Shape

Round Radiant Pear Emerald Marquise Heart Oval Princess Cushion Asscher

Common diamond shapes.

Common Diamond Buying Mistakes

The number one mistake made when purchasing a diamond is to be misled on cut quality. Cut is more difficult to define than color or clarity, and therefore often ignored or misrepresented. Common issues include:

The Federal Trade Commission (FTC) guidelines for jewellery retailers state that any seller-stated color or clarity grade must be within 1 grade of what it is appraised at by a qualified independent appraiser. This means that if you purchase a diamond that the seller represents as G/ VS2, and it later appraises as H/SI1, you have no legal recourse with the jeweller. Unfortunately, this leeway encourages jewellers to inflate their grades; a jeweller who is confident he has a G color diamond is free to represent it as an F.

It is impossible to accurately judge the clarity and color of a diamond once it is set. Flaws are easily hidden under prongs, and color is obscured by the reflections from the setting itself. Do not purchase a diamond over $2,000 without seeing it loose (preferably with a magnifier), so that you can see first hand what you are getting. No retailer, dealer, or wholesaler ever has to buy high value diamonds already set; you shouldn't either.

Color grading is notoriously difficult. GIA goes to great lengths to create standardized environments and training for color grading. Do not accept the jeweller's grade as a substitute. If a jeweller gives a color range (e.g. "This diamond is color grade G/H") you can be sure the diamond has not been graded by any lab, much less GIA, and the color grade is not reliable.

If you have doubts about the color grade you are given on a diamond, ask the jeweller if you can compare it to his in-house master color set. A master color set is a standardized set of cubic zirconia stones showing the various color grades. By holding your diamond up to the master set, you should be able to see where it fits on the GIA color spectrum.

Without a master set, or other objective measure, be very careful when comparing color in diamonds. By making invalid comparisons, a jeweller can often sell a customer up on color. For example, a customer is shown two diamonds, one described as "G" color, one described as "H" color; the customer sees that the color distinction is obvious, and decides they should move to the higher color. However, problems with this approach include:

Jewellery store lighting is designed to make diamonds look their best (for example, using specialized lighting to emit a spectrum shifted towards blue will make a yellow diamond appear whiter). When considering any diamond, ask to see the diamond in normal lighting, meaning out from under the spotlights. Options include taking the diamond outside the showroom area where standard office lighting is prevalent, or to a skylight, atrium, window or direct sunlight. You will want to see how your diamond looks under these conditions since they will be the norm once you own the diamond.

Be aware that diamond carat weights are often rounded up. For instance, a 0.69 carat diamond might be described as 0.75 carat. Always ask for the exact carat weight, and the price per carat, so that you can easily and accurately compare diamonds.

Ask to see a copy of the GIA Grading Report for any diamond you are considering. Do not purchase from a jeweller who is unwilling or unable to show you the certificate for a diamond prior to purchase.

Understand the distinction between a GIA certified diamond and a diamond that has been certified by a GIA trained gemologist. In the first case, the diamond has been graded at an independent GIA facility, in a standardized environment, by GIA technicians who have issued a GIA grading report for the diamond. In the second case, the diamond has been graded by a jewellery store employee who has been trained by GIA. The diamond has no GIA certification, and it is unlikely that the diamond was actually graded in strict accordance with GIA standards.

Remember that roughly 1/3 of diamonds have been treated in some way. While these treatments may make a diamond look better, they can have a negative impact on both the value and stability of the diamond. One benefit of diamonds certified by a reputable lab is that any treatment will be prominently disclosed. Without this disclosure, it is impossible for the average customer to recognize a treated diamond.

Often, diamonds (and settings) offered in a jewellery store have no price tag, only a style number or bar code. Alternatively, the jeweller may have a price printed, but use a calculator to figure the discount on each diamond you ask about. Both situations allow the retailer to adjust the price on the spot, based on what he believes you are willing to pay. Be very careful, as the retailer has more experience and more information than you do.

Diamonds virtually never sell for less than their true market value. Sales and coupons do not offer the opportunity to purchase a diamond for less than its value, only for less mark-up than the days it is not on sale. Traditional jewellery stores carry a much higher mark-up on diamonds than do online retailers. However, in return you receive face to face service and a chance to see the diamond before you buy.

Jeweller Warranties & Guarantees

Most jewellers offer a set of warranties and/or guarantees with every purchase. While return and trade-in guarantees are valuable (provided there is no fine print), other offers may be of less value than they first appear. When reviewing a jeweller's policies, always:

Protecting Your Diamond

If you need to leave your diamond with a jeweller (to have it set in a ring, or to have an existing ring cleaned or repaired), but are concerned about the (remote) possibility that the jeweller may switch your diamond for a diamond of lesser value, take one or more of the following precautions:

What Reduces The Value Of A Diamond?

It's important to understand what makes diamonds so expensive and its even more important to know what reduces the value of a diamond. Let's find out which characteristics lower the price and how to avoid overpaying for low-quality diamonds.

Visible Internal Flaws

Diamond clarity grades are based on how visible the inclusions are when looked at with a loupe or with the naked eye.

One of the main characteristics that reduce the value of a diamond is the number and visibility of inclusions (internal flaws) such as black spots crystals feathers etc. These internal flaws detract from the value of diamonds if they are easily seen from a normal viewing distance or are located close to the centre of the diamond when viewed from the table (top).

It's also important to mention that the closer a flaw to the surface of the diamond, the more likely the inclusion is to weaken the internal structure of the gem.

Visible Internal Flaws

Visible internal flaws.

Chips & scratches

If a diamond's surface has been chipped or scratched, the value of the diamond will go down and depending on how big and numerous these flaws are, the price can go down significantly.

For example, if you accidentally scratch or chip your diamond, the diamond is likely to crack or even break in the same place if hit again. This risk makes your diamond cost cheaper.

There is no way to repair a chipped or scratched diamond without recutting. This process involves removing the chipped part. You come up with a smaller diamond that has a lower carat weight and costs less as a result.

Diamond color - yellow tints

The most desirable diamonds are the ones that have colorless or near colorless grades and there is no surprise that visible yellowish tints lower the diamonds color grade.

Since diamonds with yellow tints are not that highly sought-after, they cost less than colorless diamonds do. Moreover, the stronger the yellow tint, the greater the drop in price.

However, the yellow tint in a diamond can be masked when the diamond is set in yellow or rose gold. In this case, the tint will blend with the color of the metal and becomes less visible, making the diamond look colorless.

Diamond Color

Diamond color.

Disproportional or poor cut

The diamonds cut quality determines how light entering the diamond will reflect back to the observer.

For instance, if a diamond has a too shallow or too deep cut most of the light entering the diamond will leak out without being reflected. This will result in low brilliance and sparkle.

The closer a diamond's cut to the ideal proportions, the more brilliance and sparkle it has, and the more valuable it will be.

As a general rule, diamonds with Poor and Fair cut grades tend to be cheaper than those with Good. Very Good or Excellent grades, all else being equal.