Why you should never buy a diamond without the right independent certification

There is no one official diamond grading institute deciding the cut, colour, clarity and carat weight of each specific diamond. While the cut and carat weight are relatively objective measures of a diamond, the colour and clarity are more subjective to arrive at.

There are several grading institutes which provide grading services of natural diamonds and the accompanying certification.

The credibility of each grading institute is largely determined by the consistency of how it grades each diamond.

In this respect the GIA is generally regarded as the most consistent with the IGI, WGI, HRD and EGL considered respectable alternatives.*

In some cases the diamond grading is performed by the retailer or a related entity rather than an independent institute. This is clearly a conflict of interest as the better the grading awarded to that diamond the more that entity stands to benefit from it.

That's why Pobjoy guarantees that each solitaire diamond we sell is graded and certified by only the most respected and recognised independent grading laboratories and institutes in the industry, of which the GIA is considered the most consistent.

Each diamond certificate details the specifications of that diamond and is an independent assurance of it's quality and integrity.

* Independent Source: 'The Diamond Pro'


Before diamond jewellery, polished loose diamonds and coloured gemstones are presented to you we carry out additional verification for added peace of mind. Using an industry standard thermo and electric probe all our diamonds are checked for authenticity independently from the certification provided. This technology does not facilitate a detailed grading process but assures that the diamonds and semi precious stones are real and not laboratory grown or some other type of simulant.

The results are kept on record with other detailed notes including certificate numbers and photos for each of our customers in electronic format for future reference. This also means that we are able to verify items returned to us, for example for polishing, and before sending back to you.


For diamond set jewellery where the individual carat weight of each stone is generally less than 0.20 (or '20 points') we are usually able to provide a third party certificate of grading verification. For example, a Hatton Garden Diamond Laboratory certificate provides a photo of the item, the grading of the precious metal used and the diamond grade.