Choosing the right diamond takes experience, skill and time. We ensure that all of our team at Jack Jordan Jewellers are highly trained to carefully select only those diamonds that are a fantastic quality.
There are many factors to consider when selecting a great quality diamond so that it will sparkle to its maximum potential. It is important to consider all aspects of the diamond grading scale, allowing for the right combination between characteristics …… you can trust in our experience to bring you a high calibre diamond alongside value for money.
For your information we have details of the characteristics of a diamond below that are recognised and used daily in the jewellery trade.


A diamond’s weight is measured in units called carats, each equivalent to approximately one fifth of a gram. The word derives from the name for the tiny seeds of the carob tree, which were traditionally use to weigh diamonds in the ancient Middle East due to their uniform round size. A carat is often expressed in points (1/100ths of a carat) so that a half-carat diamond measures 50 points for example. The carat weight of the diamond measures not just the surface or width of the gemstone but the whole dimensions including depth.


The trace of colour often seen in white diamonds is caused by the presence of nitrogen atoms. With the exception of fancy-coloured diamonds, as little colour as possible is desirable. Colour is graded using the GIA scale from D to Z, as shown below. Some diamonds can exhibit a phenomenon known as fluoresence under ultra-violet light.
The “colour” of a diamond is actually graded on how colourless it is to display a bright white sparkle. The gradings start at D for colourless. Unless you are under laboratory conditions, you would not be able to see any difference between D, E, F colour, meaning you are paying for something that you will never be able to see. These particular diamonds do also carry a premium price tag. A good colour for a diamond is in the G,H,I region which all of our diamonds are graded as a minimum. Lower than this from J downwards and you can start to see a hint of yellow, which drains the natural beauty of the diamond.


All diamonds were formed millions of years ago and display natural characteristics in the form of inclusions, which can block the light. These natural inclusions are like natures fingerprints within the diamonds and no two diamonds are the same. The higher on the scale you go, the less inclusions there are within the diamond, which offers more reflection on the facets and therefore sparkle. Some of the higher graded diamonds in the region of flawless and internally flawless again carry such a premium that you just don’t see them on the market. A good grading to go for is between the SI (slight inclusions) and I1 grading. Lower than this and you would start to see little black dots in the diamond affecting the overall beauty.


The term cut is used to describe the accuracy of the angles and proportions of the facets of a polished diamond. This accuracy governs the interaction between the diamond and light, greatly determining the diamonds overall appearance. Put simply, more accuracy equals greater brilliance. A well-cut diamond allows the maximum amount of light entering through the top of the diamond to be reflected back to the viewer, resulting in a high level of brilliance and fire. Well-cut diamonds are more sought-after than those that are too shallow or deep. As the only factor influenced by man, Jack Jordan Jewellers are extremely particular about the cut grades we select for our diamonds. With cut it is important to note that it is not just the shape of the diamond but also the dimensions to which it is faceted. The round brilliant cut is the shape which offers the maximum sparkle out of all of the cuts available. The other cuts below are rarer and can often demand a slightly higher price but do offer a different type of reflection.


The shape of a diamond is very much a personal choice and each cut displays different levels of reflection and refraction which give the diamond its own unique sparkle.

More information

Every diamond measuring over 0.50ct sold by Jack Jordan Jewellers comes with a complimentary valuation for insurance purposes.  This provides you with additional reassurance and a record of the specific diamond characteristics. 
We can also provide independent certificates from the world renowned GIA laboratory upon request for an independent fee.
Jack Jordan Jewellers also ensure that all of our diamond suppliers trade in compliance with The Kimberley Process Certification Scheme by providing us with written guarantees of ethical sources for every product.
All diamonds sold by Jack Jordan Jewellers are also guaranteed to be natural and free of any enhancement or treatment. 

Contact us

For the very best in jewellery services across the Leigh area,

contact Jack Jordan Jewellers today

Call us on 01942 604 853, or send an email to mike@jackjordanjewellers.co.uk