Carat • Clarity • Colour • Cut
These four characteristics are used as a guide for grading and purchasing diamonds. Each 'C' is reflected in the overall value of the diamond.
The Gemological Institue of America, GIA, the most recognized, as well as others such as, the European Gemological Laboratory (EGL), and the International Gemological Institute (IGI), have developed various grading and identification systems used to classify diamonds. Each lab has it’s own reputation and that reputation is taken into account when looking at a given grade of a diamond. For more information go to: www.gia.edu or www.thediamondbuyingguide.com.
A short overview:
Carat (Weight)
The size/weight of the diamond. There are certain ‘magic’ weights that affect the value of the stone at the ¼ point marks, such as 0.25ct, 0.75ct, 1.00ct, etc. Prices will increase when the diamond weight is within 0.03ct of the ‘magic’ weight. The larger the diamond, the more rare it is and is therefore reflected in it’s value.
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Clarity
This characteristic refers to the imperfections of the stone. The scale includes flawless, internally flawless, very very slightly included, very slightly included, slightly included and included. (F,IF,VVS1,VVS2,VS1,VS2,SI1,SI2,I1,I2,I3) the term inclusion helps to identify the stone and shows it’s individualaity from any other stone. The purpose and size of the diamond reflects the ideal clairity to be used. For example, for diamond earrings which are far from the admirer, si quality may be used, whereas for an engagement ring, the clarity of the diamond considered good from a G/H colour & better, & a SI1 clarity & better.
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Colour
While most diamonds are colourless, referred to as white-white, diamonds are available in an assortment of colours. The range of colours such as red, purple, blue, green and black, and all the colours in between, are a result of the various natural factors present during the diamond’s growth. Any colour that is not white or faint yellow is considered a ‘fancy’ colour. The standard colour scale is classified by letter: D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z for colourless diamonds, the closer the diamond is to the ‘d’ classification, the more valuable the stone is. For coloured diamonds, the more intense the colour, the more valuable the stone.
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Cut
Any shape other than round is classified as a ’fancy’ cut including oval, princess, radiant, emerald, heart, pear, marquise, trillion, half-moon and baguette.
When choosing a stone, for an ideal cut, the stone will shine with an ‘ideal’ brilliance that is so powerful and beautiful that it will make the stone look bigger, whiter and hide any small imperfections. A grading scale exists to measure both polish and symmetry: poor/fair/good/very good/ excellent. This grading scale complements the other characteristics such as the depth of the stone, and the facets proportionate to each other and the size of the stone.
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