The earliest references to diamonds can be traced to India, which remained the most significant source of diamonds till at least 1725, when they were discovered in Brazil. Some of the biggest and most famous diamonds in the world were mined in Golconda, in present-day Telengana.
92% of the world’s diamond pieces are currently cut in Surat, Gujarat, in western India. The quality of gemstone-grade diamonds is assessed and certified according to the 4 Cs, the standard set by the Gemmological Institute of America (GIA).
The 4 Cs of the diamond
Until the middle of the 20th century, there was no agreed-upon standard by which diamonds could be judged. The Gemmological Institute of America – GIA – devised the 4 Cs, which have become the universal standard today in assessing the quality of diamonds anywhere in the world. This means that:
The quality of diamonds could be communicated in a universal language
A customer would understand, exactly, the diamond that was being purchased
These 4 Cs are:
Colour
Clarity
Cut
Carat Weight
Colour
The finest diamond is colourless, like ‘a drop of pure water’. That is why a perfect diamond is referred to as a ‘of the finest water’. The quality of most gem-stone quality diamonds is determined by the absence of colour.
GIA’s A-to-Z diamond color-grading scale is now widely accepted as the industry’s standard grading system. D represents colourlessness and proceeds to Z with increasing presence of colour. These differences are very subtle and cannot be seen with the naked eye. It takes an trained eye to grade diamonds by colour, which marks a huge difference in the quality of the diamond as well as its price.
Today, coloured diamonds are becoming popular. These occur naturally, but can also be treated to produce colours like yellow, pink, black and so on. These are called fancy-colour diamonds.
Clarity
Diamonds are composed of carbon and are formed when exposed to tremendous pressure and heat deep within the belly of the earth. During this process, internal characteristics called inclusions and external characteristics called blemishes are formed.
In determining the clarity of a diamond, the number, relief, position and size of these inclusions are evaluated along with the external appearance of the stone. The more flawless a diamond is, the greater its clarity and price.
Diamond clarity is determined with the use of a 10x magnifier.
Flawless – Fl (loupe-clean)
- No inclusions or blemishes visible under 10x magnification
Internally Flawless – IF
- No inclusions visible under 10x magnification
Very, Very Slightly Included – VVS1 and VVS22
- Inclusions so slight that it is difficult even for an expert to see them under 10x magnification
Very Slight Included – VS1 and VS2
- Inclusions are observed with effort under 10x magnification, but can be characterised as minor
Slightly Included – SI1 and Sl2
- Inclusions are noticeable under 10x magnification
Included – I1, I2 and I3
- Inclusions are obvious under 10x magnification and affect transparency and brilliance
To a lay-person a VS1 and S1 diamond may look alike, but there is a huge difference and only an expert can tell them apart.
Also, a ‘flawless’ diamond is called ‘loupe-clean’ if, after an examination by an experienced grader with a loupe 10X (corrected for spherical and chromatic aberration), it has been found free of internal characteristics.
Bar Setting
In Bar Setting, a thin U-shaped metal bar is used to hold the diamond or gemstone. In the case of many diamonds in a piece, a bar is placed between two diamonds. Bar setting is typically used in rings and where the stones have to be set in a row. This makes the diamond look bigger and protects the girdle or edge of the stone.
Pavé Setting (pronounced paa-vey)
When diamonds are set into small holes in the metal, it is called Pavé Setting. This allows for the maximum number of stones to be set, with minimum visible metal. Literally, the metal is ‘paved’ with the diamonds/gemstones. Only small diamonds – 1-2 cents or lesser – are used in pavé setting.
Tension Setting
This is a modern technique in which tension is used to hold the diamond/gemstone. It creates an illusion of the stone ‘floating’. The stone appears to be suspended with metal on either side. It is held by pressure and there are no prongs or bars in tension setting.
Illusion Setting
In this kind of setting, a tiny bit of shiny or reflective plate/foil is used to create the illusion that the stones used are larger than they actually are. The prongs are more decorative in illusion setting and, in recent years, are also rhodium-plated, even if the metal used is yellow or pink gold.
Invisible Setting
This is a technique used to set diamonds in such a manner that hardly any metal can be seen. Only the stones are seen, the metal that holds them is ‘invisible’.
Pressure Setting
A combination of illusion and tension settings, this technique uses seven stones – one stone surrounded by the others -that are fused together with pressure to look like a solitaire. This is a very popular setting. Four or nine diamonds in pressure setting look like a single square or princess-cut diamond.
