Diamond Buying Guide (The 4 C's)

Buying a diamond is an important purchase in anyone’s eyes. This small gem can cost similar to your first car or more and so you need to have the knowledge to purchase in confidence.

The Four C’s + 1

Traditionally purchasing a diamond consisted of thinking about the 4 C’s at Nolan & Hilsers the Jewellers we bring you the extra confidence in us and our products. In business for over 100 years we know jewllery and specialise in Diamond Jewellery, let use show you our selection and explain the other four c’s to you

Diamond Buying Cut


The way a stone is cut is very important, there are two things here to consider here, you have the shape of the stone and also the quality of how it is cut. These two factors can contribute to the brilliance of the stone and how much light it reflects.


The various stone shapes is the easier of the two to explain. Diamonds and gemstones are cut into various shapes and sized stones depending on the raw material they are coming from and where they are to be set. A diamond may be cut in a variety of shapes including Round Brilliant(Circular looking from above), Princess Cut (Square looking from above), Emerald Cut (Rectangular from above), Marquise Cut (Cats Eye shape from above) and many others.

Diamonds can be cut in many shapes including Oval, Boat, Square Cushion, Princess Cut, Radiant, Standard Round, Asscher, Rectangular Cushion and Marquise


Various stone shapes can be cut to different proportions. Depending on how they are cut there will be various proportions to the cuts. It is important that there is a good ratio in dimensions. This will mean that you will have the best brilliance and show off the stone quality.

Diamond Cut Proportions, too shallow, correct proportion and too deep

Diamond Buying Colour

Diamond colour grade is actually in reference to the stones lack of colour, ranging alphabetically from D-Z. D being colourless and Z having noticeable colour. Stones carried by Nolan & Hilsers the jewellers are all graded at H Colour and above to ensure that any natural colour present is typically undetectable to the naked eye.

Diamond colour is graded by the lack of noticeable colour.

Diamond Buying Carat Weight

As seen in the cut of the stone above the proportions of a cut stone are within certain ratios. The combination of these give a certain volume of Diamond material. This overall volume is the Carat weight of the stone. It is the density of the stone.

Diamond Buying Clarity

Just as a sky will have clouds in it, diamonds are naturally occuring materials. This may mean they contain imperfections known as inclusions. These inclusions can take a few forms, dot like specs of black, hairline white lines or smokeyness in the stone. The clearer the stone the more expensive the stone. Look at the chart below, the red in each stone is the inclusions as they would be seen.

From VVS1-VVS2 you may need to use a lens to view the inclusions. From grades SI1 onwards inclusions may be seen by a customers naked eye without magnification.

Now you have an idea of Diamonds why not browse some on our store here.

Have A Question about Diamond Buying?

Contact us by phone at 066 7121834 or 066 7122095 from Ireland, or email at online@nandh.ie