There is much more to a diamond than what meets the eye. While most of us have heard the words Cut, Carat, Colour & Clarity, you need to know exactly what it means to pick out the best diamonds for yourself right within your budget.


The cut of a diamond is a manual process and refers to fabricating the stone from its raw outlook into a particular shape. The cut affects a diamond’s value, shine and life. There are different diamond cuts that have been developed over the time.

According to GIA (Gemological Institute of America) Cut Scale – Excellent, Very good, Good, Fair and Poor are gradients to shape a diamond for its market value.

The standard round brilliant is the shape used in most diamond jewellery. All others are come under fancy shapes that include the marquise, pear, oval and emerald cuts. Hearts, cushions and triangles are newer and are gaining popularity in diamond jewellery trade.



Larger the diamond (means heavier), higher the price. Though cut, clarity and colour are other three important key factors.

A carat is defined as the measured mass of a diamond. According to standard, 1 carat equals 200 milligrams. Though it is not the only factor, it plays a major role in defining the selling price of a diamond.


GIA applies a grading scale from “D” (colourless) to “Z” (light yellow) to classify the colour of diamonds. Diamonds also come in different colours. The blue are called fancy coloured diamonds and fall under a different grading scale. They are colour-graded by comparing them to other coloured stones under controlled light and precise viewing conditions.

Each Diamond reflects colour and shines because of the elemental impurities and structural difference inside it. Like Type I diamonds have nitrogen impurities (usually reflecting light yellow colour) while Type II has no Nitrogen impurities (pink, blue or red coloured).


Diamond has a wide band gap corresponding to the deep ultraviolet wavelength. This means a pure diamond should transmit visible light and must appear as a clear colourless crystal.




Diamonds are formed under extreme pressure and heat applied to carbon in depths of the earth. It’s only natural then to expect some imperfections both inside and on surface. These impurities hamper the shine of a diamond and are mostly structural defects. In some cases, it could also be other elements like a tiny piece of diamond embedded in another.



Hallmark is an official symbol for precious products like gold and silver. It standardizes their traits or the characteristics that determine the purity of a substance.

Price of these products is based on this characterization only. To make the trade more transparent and reliable, governments of different countries have been working to standardize the fineness of these precious items.


Diamond Certificate

Hallmark can’t be engraved on to every diamond’s surface. Instead, every diamond comes with a certificate that describes the shape, size, clarity, colour, cut and few other charactersticks of a diamond. Every diamond that is bought or is being processed is under the government radar, has a certificate. In India, GII (Gemological Institute of India) issues these certificates. Apart from GII, government approved independent laboratories also test diamonds and issue certificates.

Please ensure that you ask for a certificate every time you purchase a diamond, even if it is a known jeweller.


BIS Hallmark Jewellery

In India, a BIS hallmarked jewellery is the proof of standard mixing of metals as per government rules and ensures fair trade while buying as well as selling of the same. Every time you buy gold or silver jewellery, look for the hallmark sign on the inside.


BIS hallmark for gold jewellery consists of several components:

  • The BIS logo
  • A three digit number indicating the purity of the gold in part-per-thousand-format. A BIS 916 hallmark would certify to a purity of 916 per 1000, that is 91.6%, translating to a 22 carat purity of gold
  • Logo of the assaying centre
  • A code denoting the date of hallmark.
  • Logo of the jeweller



  1. Certification makes comparison between the diamonds easy.
  2. Certification ensures the replacement value of the stone.
  3. Certification plays a huge part in the resale value of the “precious”.
  4. While reselling, a certificate ensures the legality of the source.
  5. Certification gives peace of mind that one was not fooled on value-for-money trade.