Diamond Buying Advice Guide

At PJS we have a lot of knowledge of diamonds; we’ve worked with many beautiful pieces of diamond jewellery during our years in the industry.

We want you to feel fully equipped with the expert knowledge required to ensure you get the best for your money and are delighted with your purchase. That’s why we’ve put together this guide to diamonds.

There are four important areas you should consider when purchasing diamonds, these are cut, colour, clarity and carat.

Diamond Cut

Diamond cutting is a precise science in itself; it is the shaping of a rough diamond, into one of the cuts of gemstones ready for setting. 

The GIA classifies cuts of diamond into three types: Brilliant Cuts, Step Cuts and Mixed Cuts.

This diagram shows the most popular cuts of Diamond.

Diamond Colour

A perfectly pure diamond is totally transparent, and has no hue or colour.

However, most diamonds of gemstone quality have a slight tint to them and are

known as ‘White Diamonds’. Many people are unaware of the variety of colours diamonds occur in, from a deep blue colouration to vibrant pinks!

Most people want white diamonds, and because of the variety of different colours available and the implications this has on the cost of the stone the GIA has developed a Colour Grading Chart.

Diamond Clarity

Clarity is the measure of the internal defects located within diamond.

These defects are called inclusions, and will affect the quality and therefore the cost of the diamond. Inclusions occur whilst the diamond is forming, and are sometimes structural imperfections, foreign materials or tiny cracks that appear white and cloudy.

Most inclusions do not affect the diamonds structural integrity but can, dependant on the level of inclusions affect the diamonds ability to scatter light.

It is important to remember, that inclusions are entirely normal within diamonds, and an entirely clear stone would be exceptionally rare.

Diamond Carat

Carat, the final C, and probably the most easily misunderstood. 

The term Carat relates to the weight of the diamond and not its physical dimensions. One Carat equals 200 milligrams of weight, and the term is normally abbreviated to ‘ct’, Diamonds weighing less than 1ct in weight are referred to in points (pt) and there are 100 pts per carat.

The larger the diamond the rarer and the more in demand that stone will be. A 1ct solitaire ring, of the same quality will be considerably more expensive than a 1ct ring made up of many smaller stones.