Buying a diamond can be a daunting task if you’ve never looked into them before. There is a lot of information to keep in mind for buying a diamond, but there is a great reference guide you may have heard of! The 4C’s.
Carat is a measure of gemstone weight. One carat (1.00ct) is equal to 0.20 grams. A carat is divided into 100 “points”. So when we refer to a 0.50ct diamond, it could also be called a 50 point diamond.
It is important to note that carat weight refers to the physical weight of the diamond and not its dimensions. Fewer than one in one million diamonds are large enough to create a one carat diamond. As you reach closer the one carat size, a diamond price increases in price exponentially.
Diamonds naturally occur in all colours of the rainbow, colourless being the most popular.
The GIA colour grading scale ranges from D-Z, with D being colourless, and Z being a tinted colour. The less colour a diamond has, the more valuable it is.
Generally speaking, when looking at a diamond from the top, you start see a hint of yellow starting from colours I – J and below.
Next to cut, colour is the most important grading factor because it is noticeable and visible to the naked eye. For engagement rings, we would recommend I colour or better.
Diamonds are formed deep in the earth in extreme heat and pressure. As a result of this millennial long process, small imperfections can be formed in a diamond. These natural characteristics inside the crystal are referred to as inclusions, and blemishes if they are on the surface. The clarity of the diamond is graded based on these flaws. Diamonds that contain a large amount of inclusions and blemishes can be less brilliant than other diamonds because they can block the path of light through the diamond.
An inclusion’s position inside a diamond can play a large role in their visibility. Diamond cutters are cautious when cutting diamonds to ensure that the smallest amount of inclusions can be visible through the table (top) of the diamond.
Many diamonds are graded using the eleven point diamond clarity scale created by the GIA. The number, size, colour, reflectivity and position of every flaw visible under 10x magnification is considered when identifying a diamond’s clarity.
Cut is one of the most important factors when looking for a diamond as it has the largest impact on the overall performance. It specifically refers to the quality of the cut and should not be confused with the shape of the diamond, as only certain shapes are graded on their cut.
The most popular and most vivid shape is the round brilliant cut, which was invented in 1919 by an engineer and mathematician, Marcel Tolkowsky.
The most important factors in cut grading are:
Brightness: The amount of white light reflected from a diamond.
Fire: The scattering of light into all colours of the rainbow.
Scintillation: The sparkle of the diamond and the patterns of light and dark areas of the diamond.
In order to maximize sparkle, a diamond must be cut to specific parameters. The grading is based upon the symmetry of the facets, durability of the diamond and the cleanliness of the surface polish. According to the Gemological Institute of America (GIA), the cut grading scale is categorized into 5 grades: Excellent, Very Good, Good, Fair and Poor.
In keeping with top industry standards, we chose only to stock the highest quality of diamonds of very good quality or better. Our store specializes in GIA Excellent to Very Good cuts, AGS Ideal to Excellent cuts and Forevermark Excellent to Very Good cuts.
Certification (the 5th C)
Certification is important when buying a diamond. Certificates for diamonds usually come with diamonds over 30 points or 0.30cts. Certificates come from a 3rd party gemologist group such as GIA (Gemological Institute of America), AGS (American Gem Society), and EGL (European Gemological Laboratory). These are the most recognizable types of gem certification. A certification documents the 4cs of the diamond and any unique registration marks. The main thing to know here is each company grades diamonds differently. In the end they use the same grading ratings, but how they decide what diamond goes into what category is different. For example, GIA and AGS certificates are very strict in their grading and therefore more sought after. EGL tends to be slightly more lenient in their ratings. This means an EGL rated VVS diamond could be considered a VS or even SI in GIA and AGS standards. Their rating are not wrong, they just have a different scale they judge by. So typically an EGL VS clarity diamond will cost less than an AGS rated VS diamond.