Nobody likes feeling out of their depth, least of all when it comes to a big purchase like a diamond or engagement ring. Familiarise yourself with this diamond terminology, and you’ll soon be seen as the jewellery connoisseur.

Certified

If a diamond is certified, it is accompanied by a document of authenticity and grading from a gemmological laboratory. Most diamonds of 0.30ct or higher should be certified, as their value is determined by their exact grading. Naturally, the importance of having a diamond graded by an independent 3rd party, i.e. a laboratory, becomes more and more important as sizes and prices go up.

The certificates most widely recognised on the South African diamond market come from the GIA—the globally undisputed gold standard in diamond grading—and EGL. Independent certification ensures your diamond’s quality is accurately disclosed, protecting your purchase and providing complete peace of mind.

Cut

This term commonly refers to the shape or cut style of a stone (pear cut, princess cut, etc.)

However, a stone’s cut also refers to the evenness, symmetry and angle of its facets. A well-cut diamond with a well-polished surface will have noticeably superior brilliance when compared to a poorly cut counterpart. When purchasing a round brilliant diamond, look for the term ‘Triple Excellent’ (or Ex/Ex/Ex on a GIA grading report). This means the diamond has achieved the highest possible grade in three key categories: Cut Grade, Polish, and Symmetry.

These accolades might make a diamond slightly pricier, but the added investment will show in its shine.

Clarity

Not to be confused with brilliance, a diamond’s clarity has everything to do with its inner purity, but not necessarily much with its shine.

A diamond with a clarity grading of VVS or lower will have inclusions embedded in its crystalline structure. The noticeability of these inclusions determines their clarity grade. Generally speaking, an inclusion only hinders the beauty of a stone when it can be seen with the unaided eye. I.e. without using a magnifying glass or loupe.

Eye-clean

Even diamonds with lower clarity grading can be eye clean. This does not mean the grading is wrong, but that the nature or positions of the impurities are such that they are only visible when magnified. An eye-clean diamond with a lower clarity grading is often a great find, as the buyer gets the benefit of a low price without compromising on aesthetics.

Higher clarity is still preferable when purchasing a diamond for investment, as a stone’s value is always based on its certified clarity grading.

Fluorescence

Traces of nitrogen aggregated within a diamond’s crystalline structure can cause the stone to fluoresce. This phenomenon is most visible when the stone is viewed under UV light, where it will typically glow bright blue. This phenomenon is most visible if the stone is viewed in UV light, where it will glow bright blue.

In natural light, mild to medium fluorescence can hardly be seen. Strong fluorescence can make the diamond appear dull and, in some cases, even milky.

Fluorescence is a natural optical characteristic rather than a defect or flaw. In top colour grades (D–F), very strong fluorescence can occasionally cause a hazy appearance, which may lower market demand. However, in lower colour grades (I–M), medium blue fluorescence works to neutralise yellow tones—making the diamond face up visibly whiter without increasing its cost. Before purchasing a diamond, check the certification for any mention of this phenomenon. In some cases, fluorescence can make a diamond appear whiter, a benefit to its appearance without increasing its value.

Table

The top flat facet of a stone. When discussing diamonds, your jeweller may mention that a stone has a clean table. This means any inclusions present in the stone are situated towards the edge (or girdle), where the crown facets can easily obscure them.

Facing up white

When grading the colour of a diamond, gemmologists assess the stone from its side to avoid interference from the crown (top) facets. In some cases, when the diamond is turned upright again, it appears to be a whiter stone than its grading suggests. As with eye-clean diamonds, the buyer gets the benefit of a lower price because the stone is sold according to its certified colour grading.

ECG

Short for Equivalent Colour Grade. Diamonds are generally graded in colour according to the presence of a yellow tint caused by trace elements like nitrogen.

In the case of a diamond showing a different colour tint, the stone gets an ECG grading. For instance, if the stone shows a greyish tint, it is awarded a grading corresponding to the same intensity of colour if it showed yellow instead.

Mount

Whether this refers to a ring, pendant, or a tiara, a diamond’s mount is a piece of jewellery in its entirety, but excluding the main stone. Having a diamond remodelled would mean setting it in a completely different or altered mount.

Price barriers

The value of diamonds increases per carat as a stone goes up in size. In other words, five stones with a total weight of 1.0ct will be priced much, much lower than a single stone of the same quality and weight.

The universal standard for diamond pricing, otherwise known as the Rapaport, divides diamonds into price categories based on weight, with exponential price differences between categories. Buyers would therefore find they can spend much less on a 0.97ct diamond compared to a 1.00ct stone of the same quality. These stones might not even have a visible difference in diameter. The same goes for a stone just below 0.50ct, 0.70ct, 0.90ct, 1.50ct, 2.00ct and so forth.

Knowing the price barriers can help a buyer find a stone with an attractive size at a great price.

To view the widest selection of perfectly cut certified diamonds in Cape Town, visit Mark Solomon Jewellers today.