Diamonds

All of our diamonds are sourced from reputable Southern African and international labs adhering to the Kimberley Process, the Gemological Institute of America (GIA) being our preferred laboratory. All stones larger than 0.50 ct are accompanied by a lab certificate stating the measurements, weight, colour and clarity grade of the stone as determined by the laboratory. Lab certification on stones below 0.50 ct. is available on request.

What if I already have a diamond?

No problem. Weddings are expensive and we all try to save wherever we can. If you already have a diamond, be it a family heirloom or a diamond bought through another connection, you are most welcome to bring it along. You will not be judged.

 

What should I look out for when buying a diamond?

The four most important factors in gemstone grading are the four C’s; Cut, Colour, Clarity, Carat.

Below is a break down of each factor in descending order of impact on price:

Carat

Carat (abbreviated ct.) refers to the actual weight of the stone measured in carat. One carat is equal to 0.20 gram and is determined with a special, very sensitive scale. In the lab the weight is determined to the third or sometimes fourth decimal, a measurement not easily obtained with the equipment commonly found in the average jewellery studio.

Colour

The second most important factor influencing the price of a diamond is the colour grade of the stone. Colour grading according to the GIA’s internationally accepted grading system starts at D, which is colourless, and continues down the alphabet, growing increasingly yellow as it does. The differences from one grade to the next are so minute that they are determined by comparing the stone to a master-set in the lab under very specific lighting conditions. The value of the stone drops as the yellow component increases until it reaches a distinctly yellow hue, which is when the value starts rising again. A yellow stone with a strong hue can be several times more expensive than a colourless stone of the same size and clarity.

When we think of diamonds we normally think of white stones, but diamonds are actually available in a variety of different colours. The most common is yellow, but they also occur naturally in black, charcoal, cognac, blue, green, pink and most rarely in red. Naturally coloured diamonds of a bright, deep hue and even saturation with a brilliant sparkle are insanely expensive, much more so than white diamonds, and are not easily sourced, but they can be found if you know where to look.

Black diamonds, though often less expensive than white diamonds, are awesome in their own way, because if they are mined in the right region they are actually meteorites! Read this article on black diamonds and their origin for more information.

It is also possible to colour diamonds artificially through a process called irradiation, but these stones, though usually of a very deep, intense colour, are normally a little milky or heavily included. Labs don’t like wasting good grade stones on artificial treatments. Much of the black diamonds available on the market are the result of irradiation, so make sure you know where it was mined if your aim is to purchase a naturally coloured stone.

Clarity

Clarity refers to how many tiny cracks or bits of coal your stone has on the inside. The GIA grading system breaks it down as follows:

F – Flawless: a diamond which has no cracks, marks or inclusions either inside or on the surface of the facets at 40 x magnification in the lab. These are extremely rare and very pricey.

IF – Internally Flawless: a diamond which has no cracks, marks or any inclusions on the inside at 40 x magnification, though naturals or extra facets are present on the outside. Also very rare, also very pricey.

VVS 1 & 2 – Very, Very Small Inclusion (with two subgrades, 1 & 2): a diamond which shows tiny cracks, marks or inclusions at 40 x magnification, but which are not visible to the naked eye.

VS 1 & 2 – Very Small Inclusion (also with two subgrades, 1 & 2): a diamond which shows cracks, marks or inclusions at 40 x magnification, which are visible at 10 x magnification to the trained eye, and not visible to the naked eye.

SI 1, 2 & 3 – Small Inclusion (with three subgrades, 1, 2 & 3): a diamond which shows cracks, marks or inclusions at 10 x magnification and is visible to the trained naked eye or the very astute untrained observer, but which does not detract from the brilliance of the stone.

I 1, 2 & 3 – Included (three subgrades): a diamond which shows cracks, marks or inclusions which are visible even to the untrained naked eye, and which detracts from the brilliance of the stone.

Cut

In most commercial stones, the cut does not affect the price as much as it does on collector’s pieces. Cut refers not only to the shape but also to the quality of the lapidary work. Extra facets and skewed proportions generally detract from the brilliance of the stone, but won’t make much of a difference on stones below 1.0 ct. Round stones are generally more expensive than other shapes, but a poorly cut round stone will probably sell at a lower price than a well cut stone of a different shape. For commercial jewellery purposes, most stones on the market fall within an acceptable range of cut quality, even those above 1.0 ct, and therefore this does not affect the price much, nor is it something we advise our clients to be concerned about when selecting a diamond. Occasionally a diamond which is too deep or too shallow crosses our desks, but it doesn’t happen often and it is usually clearly visible right away. Ultimately, unless you are buying diamonds as an investment, choosing the one you find most beautiful is the best rule of thumb.

Ideal Proportions

The GIA does prescribe an ideal proportion for round stones, at which all the light that enters the stone through the table is reflected back out through the table, resulting in optimal brilliance. Your diamond’s proportions are indicated in the certificate for easy comparison.

A diamond with ideal proportions has a crown with a height of 19.2% of the diameter, a pavilion depth of 40%, a table diameter of 56.1% of the diameter of the stone, a crown angle of 41.1°, a pavilion angle of 38.7°, and a girdle thickness ranging between 1.25% and 1.75% of the diameter. A lapidary will normally choose to optimize weight retention rather than obtaining a better cut, since that has a bigger effect on price, so these measurements are not a rigid standard but are deemed acceptable if they fall somewhere near the ideal proportions. A stone which is cut too deep will appear darker and seem too small for its weight, and a stone which is cut too shallow will often lose sparkle or appear too large for its weight.