At Avanti, we source the majority of our diamonds from trusted institutions: the GIA, HRD and IGI.

Our customers can be confident in the knowledge that they are buying a piece of diamond jewellery that has been checked and approved. We also hand select non-certified loose diamonds, these are graded by the owner Alan who has a diploma in diamond grading with HRD Antwerp Institute of Gemology

Don’t be fooled by certificates issued by a retailer – many online stores do this and you are in danger of buying a diamond that’s of lesser value than you believe it to be.

For more information about GIA click here

The cut of a diamond refers to its proportions and is not to be confused with its shape. It indicates how well a diamond has been made from its original rough, uncut form and determines the stone’s sparkle, greatly affecting its price. A well-cut diamond is better able to reflect light and therefore has a greater sparkle.

The cut is determined by the body issuing the diamond’s certificate, and grades vary slightly from institution to institution. However to give you an idea, GIA’s grades are: Excellent, Very Good, Good, Fair and Poor.

The weight of a diamond is expressed in carats. Generally, the larger the diamond, the more it weighs and the higher the price. One carat is divided into 100 points so a diamond weighing half a carat could be described as weighing 0.50ct (or 0.50pt)

Another crucial element to consider when buying your diamond jewellery is the colour of the diamond. Ironically, colour grades refer to how colourless or white a diamond is! The more colourless the stone, the more sought-after it is. Diamond colour is graded from D to Z, where D is the most colourless and therefore considered to be the best. Further down the scale, the colours become more yellow and brown.

Clarity is one of the most important indications of a diamond’s quality. Almost all diamonds contain some natural inclusions – imperfections or blemishes – but the fewer there are the more valuable and rare the stone is. Clarity is graded by evaluating the size, location and visibility of inclusions.

The GIA use an 11 point scale to rate clarity: ranging from the best grade, Flawless/Internally Flawless (FL/IF) to the lowest grade, Included (I1, I2, I3).

This refers to the basic form of a diamond. There is a wide choice of shapes available and you’ll probably be most interested in this aspect, because of course it’s one of the most noticeable features. Shapes include:

• Round brilliant – by far the most popular diamond shape
• Princess
• Emerald / Octagonal
• Marquise
• Asscher
• Pear
• Oval
• Heart
• Radiant
• Cushion
• Trilliant
• Baguette

The girdle is the outer edge of a diamond and is rated in terms of thickness. Girdle size is generally defined as either Extremely Thin, Very Thin, Thin, Medium, Slightly Thick, Thick, Very Thick, or Extremely Thick. The best thickness is probably either thin or medium – it’s not too thin to be brittle and not too thick, which can mean it’s been cut too deeply and is losing light and brilliance. Download more information here

The culet is the bottom point of the diamond. It is generally graded as None, Pointed, Very Small, Small, Medium, Slightly Large, Large, Very Large, and Extremely Large. The best grades tend to be medium and anything lower; larger culets are less desirable. Download more information here

The polish of a diamond is also graded for quality and it refers to how well the diamond was finished: how clean, shiny and straight edged the facets where cut, and if any microscopic blemishes or marks were left by the polisher. A well-polished diamond is more brilliant than a poorly polished diamond. Polish is generally graded as either: Excellent, Very Good, Good, Fair, or Poor.

A diamond’s symmetry relates to the positioning and alignment of the facets (the small flat surfaces). Diamond experts look for certain things to indicate the symmetry quality, such as how straight the edges are, how many facets there are, their proportions and alignment with other elements of the diamond such as the girdle. The symmetry is generally graded using the same scale as polish.

Diamonds that emit a glow (that’s usually blue) when exposed to UV lighting, are said to be fluorescent. Because diamonds with a strong fluorescence can look hazy in ordinary light, they tend to be cheaper. This doesn’t necessarily mean they should be avoided, since most of the time there will be no noticeable sign of fluorescence, and sometimes this quality can even enhance the colour of a diamond.