Cape Town’s Premier Manufacturing Jeweller
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Cape Town’s Premier Manufacturing Jeweller

Some good-to-know diamond terminology

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 these diamond terminology and you’ll soon be the seen as the jewellery connoisseur.

If a diamond is certified it is accompanied with 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 commonly seen on the South African diamond market are GIA and EGL, both of which are internationally recognised and respected for their accuracy.

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 diamond, take heed to terms like “excellent cut”, ”ideal cut” and “triple excellent cut” also expressed as Ex/Ex/Ex. This means the stone has superior proportions, symmetry and surface quality.
These accolades might make a diamond slightly pricier, but the added investment will show in its shine.

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 imbedded in its crystalline structure. The noticeability of these inclusions determines its 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.

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, but without compromising on aesthetics.
Higher clarities are still preferable when purchasing a diamond for investment as a stone’s value is always based on its certified clarity grading.

Traces of boron inside a diamond’s crystalline structure can cause the stone to show fluorescence. 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.
Although fluorescence is not one of the four main factors in determining a diamond’s value (i.e. Cut, clarity, colour and carat weight), it is considered a defect and lowers the stone’s selling price. 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.

The top flat facet of a stone. When discussing diamonds, your jeweller may mention 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.


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.

Whether this refers to a ring, pendants or 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 completely different or altered mount.

Price barriers

The value of diamonds increase 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.

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