The 6C's of Diamond Buying | First State Auctions

The 6C's of Diamond Buying

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You would have heard of the 4 Cs of diamond buying. At First State Auctions we believe that there are 6 Cs that anybody purchasing a diamond should be taking into account.

When buying and selling a larger diamond, a Diamond Certificate is an important tool for giving accurate grading of colour, cut, clarity and carat weight (The 4 Cs). It has a dramatic effect on the price of the diamond if any of the gradings are over stated.

So we believe there should be 6 Cs to diamond buying, the 5th C being for Certificate. Unless you have a reputable, recognised and trusted diamond certificate, you can't measure accurately the 4Cs, and then you can't be certain of the correct price that should be paid.

The 6th C is for 'see'. Each diamond is unique and can only truly be appreciated by looking at it. It is very important to be aware of the 5 Cs because they dictate the price of the diamond. But the diamond should still be bought with your eyes  with which you see.


The original 4C's

Colour, cut, clarity & carat are the original 4Cs, for more information you can view the GIA videos below explaining the 4Cs. GIA is considered the final word on a diamonds authenticity and quality. GIA developed the 4Cs and the International Diamond Grading System, the grading standard adopted by jewellery professionals around the globe. 

The usefull chart below covers the GIA clarity spectrum often used to compare and value diamonds.



Why is a Diamond Certificate important?

A diamond certificate should be conducted on the loose diamond the only way to be accurate. This way the setting is not obstructing the measuring of important information that make up the value of the stone. The laboratory should also be independent of any retail or wholesale business.


Why a reputable laboratory?



So, the advice is to only buy diamonds with a reputable, recognised and trusted diamond certificate to ensure that you achieve the 5th and 6th C - the right Cost and get what you are paying for!





At First State Auctions, we believe that a Valuation Certificate can be misleading and can give the impression that the item is actually worth the amount it's valued at. This is often not correct, and is frequently over stated due to the process of valuation being very subjective.


Understanding Diamond Fluorescence



Click here to read more about GIA’s view on Diamond fluorescence …