Home Budgeting Investing Griffin and Highbury’s How-To Guide on the Diamond Grading System

Griffin and Highbury’s How-To Guide on the Diamond Grading System

For anyone interested in investing in diamonds, knowledge is key. Fortunately, there are many resources available and many rating agencies out there to help make it easier to decide whether a particular diamond is a good investment or not.

Investors should always make sure their diamonds are certified by a reputable and objective agency, like the Gemological Institute of America (GIA) or the American Gem Society (AGS). Other respected grading agencies that can be used include the International Gemological Institute (IGI) or the International Confederation of Jewelry, Silverware, Diamonds, Pearls, and Stones (CIBJO). A certificate should come with every diamond purchase; any of these organizations should be able to provide one.

A certificate is important because it shows that a complete evaluation of the diamond, something that should always include measurements with gemological instruments, has been performed by a qualified professional. Diamonds can be tampered with as a way to hide their imperfections, so consumers must make sure a professional has evaluated their diamond purchase objectively.

As Geoff Black, owner of Canadian-based diamond and gemstone dealer Griffin and Highbury Inc. comments, “No two diamonds are alike, which is why people say they are like snowflakes, and also why having them evaluated is critical.” Black goes on to recommend that all buyers use and understand the “Four C’s” method of evaluating diamonds. This is the most well-known and widely accepted method when it comes to determining a diamond’s value.


The Four C’s stand for clarity, cut, color, and carat weight.

Clarity looks at the visual appearance of a diamond and its surface defects or blemishes, as well as its internal characteristics, which are called inclusions.

The cut of the diamond doesn’t refer to the actual shape of the diamond but is based on its symmetry, which affects the overall polish. If a diamond is poorly cut, it won’t illuminate, which makes the cut extremely important when it comes to aesthetics.

The color of a diamond is the next C in the measurement system. The color looks at light refraction or sparkle. There is a numerical scale used to determine the color of a diamond, and this weighs heavily on its value. The AGS scale goes from 0 to 10, with 0 being colorless and 10 being light yellow or brown.

Carat weight should also be reviewed. Large diamonds are less commonly found than small diamonds, so value rises with the size or weight of the diamond.

Of the aforementioned characteristics, the color of a diamond is the most discernable for non-experts and has the widest variety. Diamonds occur in a variety of colors, including steel grey, white, blue, yellow, orange, red, green, pink, purple, brown, and black. A perfect diamond, which is chemically pure and structurally perfect, has no color. Depending on the rarity, colored diamonds can be much more valuable than regular ones. While white diamonds may be discounted due to a yellow hue, pink or blue diamonds can be extremely valuable, and red diamonds are the rarest and often most valuable.

Diamonds and their valuations can be much more complicated than one would expect, which is why, again, knowledge is essential, especially when it comes to investing in diamonds. For anyone looking to invest in diamonds, it is absolutely imperative to have it evaluated by an objective agency, which should be included in the services of any reputable seller. Griffin and Highbury’s owner Geoff Black adds a final caveat, “If any person or company comes to you offering to sell diamonds and doesn’t have a certificate, you should treat it as a red flag and avoid their services.”




Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Skip to content