GEMSTONE GUIDE: DIAMONDS
Diamonds are the most traditional choice when it comes to selecting a stone for an engagement ring. We can source diamonds in any colour and help you to select the perfect stone or stones for you. White (colour-less), yellow and cognac are by far the most common.
Every diamond is unique, and there are a variety of factors which affect the price of a diamond. Focus on those factors most important to you, and choose a diamond that satisfies your individual standards for beauty, quality and good value for your budget. This might be a very different diamond than someone else with a similar budget would choose.
The quality of a stone is based upon an accumulation of different factors, cut, colour, clarity & carat, otherwise known as the 4C’s. We only work with GIA certified diamonds and only use those that lie between the top of the colour scale, a D, through to G.
Every diamond certified by the GIA undergoes a thorough, independent evaluation. Here you will learn how GIA diamond grades are established, and how those grades affect the diamond’s price. Each of the four C’s (Carat Weight, Cut, Color, Clarity) is accompanied by a diamond chart illustrating the differences between grades.
Images and content in this section courtesy of GIA.
Diamonds are sold by the carat (shown as ct.), which is a unit of weight. The word “carat” comes from the “carob” seed, the original unit of measure for diamond traders. Today, a carat is equal to exactly 0.2 grams. Carat weight is unrelated to the similar sounding karat, which refers to gold’s purity.
The carat of any stone is the unit of weight it holds, not its visible size as this is related directly to its cut and spread. A heavier stone may appear smaller if it is cut deeper and vice versa. One carat (1 ct) is divided into 100 points, so a diamond of 50 points is described as a half a carat. Carat weight is the most obvious factor in determining the value of a diamond, but its important to take into consideration that two stones of an equal weight can have very different values once the aspects are taken on board.
Colour is a key characteristic. Diamonds come in a variety of colors, some of them highly prized (pinks, blues, even yellow). However in a white diamond, the presence of a yellow tint will lower the price of a diamond. The less body color in a white diamond, the more true color it will reflect, and thus the greater its value. The ideal diamond colour is graded as a ‘D’ and has the total absence of any colour. However, when colour grading fancy diamonds, otherwise known as coloured diamonds, this is the exact opposite as an intense hue is an asset, a vivid colour is required.
The diamond colour evaluation most gem-quality diamonds is based on the absence of colour. A chemically pure and structurally perfect diamond has no hue, like a drop of pure water, and consequently, a higher value. GIA’s D-to-Z diamond colour grading system measures the degree of colourlessness by comparing a stone under the controlled lighting and precise viewing conditions to master stones of established colour value.
The clarity of a diamond is assessed by how many imperfections it holds both internally and externally. These marks and flaws in the stones are called inclusions. Almost all diamonds contain minute traces of non-crystallised carbon, as organic products this is nature’s way of making each stone unique.
Evaluating diamond clarity involves determining the number, size, relief, nature, and position of these characteristics, as well as how these affect the overall appearance of the stone. While no diamond is perfectly pure, the closer it comes, the higher its value.
The GIA Diamond Clarity Scale has 6 categories, some of which are divided, for a total of 11 specific grades. Many inclusions and blemishes are too tiny to be seen by anyone other than a trained diamond grader.
When a stone is perfectly cut, light rays from all angles are bent towards the centre of the stone to then reflect back out giving diamonds their characteristic ‘sparkle’. A diamond that is cut too deep will allow light to escape through its sides, where as a stone that is cur too shallow, ‘leaks’ light through the bottom giving a dull appearance.
Diamonds are renowned for their ability to transmit light and sparkle so intensely. We often think of a diamonds cut as shape (round, oval, marquise, pear), but a diamond’s cut grade is really about how well a diamond;s facets interact with light.
Precise artistry and workmanship are required to fashion a stone so its proportions , symmetry and polish deliver the magnificent return of light only possible in a diamond.