First of all, a diamond should be accompanied by one of the world's three leading certificates; the HRD or IGI in Antwerp and the USA based GIA.

Other certification may be less accurate.

Diamond Grading

The main quality characteristics of a diamond are the 4 C's: Carat ( weight ), Clarity, Colour and Cut.
They are indicated on the Certificate Moreover they are the preliminary examinations.

• Carat
• Clarity
• Colour
• Cut

Together with the 4C's, the shape, fluorescence and measurements of a diamond are also mentioned on the certificate. The shape of the diamond is the form in which the stone is polished. Apart from the popular round brilliant, the pear, oval, marquise, heart, emerald and princess cut are also much in demand.

Fluorescence is the effect whereby invisible ultraviolet light is transformed into visible light. some stones light up spectacularly in the dark when irradiated by long-wave ultraviolet light. The fluorescence grades are: nil, slight, medium and strong

The measurements of a diamond are expressed in millimetres. For round brilliant, the certificate mentions minimum diameter - maximum diameter x height; for all others shapes it mentions length x width x height.

Carat

The weight of a diamond is expressed in carats 1ct = 0,2 gram. This accurate weight is very useful for the identification of the stone. The metric carat, which equals 0,200 gram, is the standard unit of weight for diamonds and most other gems.
If other factors are equal, the more a stone weighs, the more valuable it will be.

Clarity

The best clarity grade is called " loupe clean or internally flawless", meaning ' clean when viewed through a loupe '.The other clarity grades depend on the number, size, brightness and location of the characteristics present, ranging from VVS (very very small internal characteristics which are very hard to find even with the loupe) to P (visible with the naked eye).

Clarity characteristics are classified as inclusions (internal) or blemishes ( external ), Very few diamonds are loupe clean that means, show no inclusions or blemishes when examined by a skilled grader under 10 x magnification.
If other factors are equal, flawless stones are most valuable

Colour

The colour of a diamond is determined by comparing it to an internationally approved series of master stones under standardized artificial light, equivalent to Northern daylight.

Cut

A diamond should be cut in Antwerp where you can find the best craftsmanship on the market: It's the cut that makes a diamond sparkle !
On an international certificate, the description of the cut is split into a separate description of the proportions ( angles of inclination and proportional relations between the various parts of the stone ) and finish, which is mainly concerned with the positioning of the facets

Why should a diamond purchase in Antwerp be any better than in Paris ?

To begin with, Antwerp is the very source of the diamond trade with as much as almost 80% market share, in other words: a Paris diamond most of the times is bought in Antwerp before it was put up for sale in New York.
Secondly, Antwerp has always been the only diamond city in the world with three diamond-cutting schools where young people are moulded into the world's finest craftsmen in diamond polishing.

Antwerp ?

Also called Antwerpen in Flemish.
Anvers in French.

Diamond city of the world, 2nd largest port of Europe on the river Scheldt, in Belgium.

Home town of Jewels CAEYERS Juwelen