Diamond Buying Guide: Looking Through the Jeweller’s Loupe


WHEN it comes to buying jewellery, nothing beats diamonds for pure class and elegance. Yet we don’t get to buy diamonds every day. So when you do venture out diamond shopping – usually for a huge special occasion like an engagement – how do you know you’re getting the best diamonds, at the best price?

Here, our jeweller explains in easy terms what you should look for.


Luckily, it’s easy to judge the quality and value of a diamond by using 4 fundamental criteria. If you’ve been researching diamonds, you’ll already know that these are called ‘The Four Cs’ – cut, colour, clarity and carat. Let’s take a look at how you can determine the best choice for you, out of each of these factors, very easily.

Diamond Buying Guide: Looking Through the Jeweller’s Loupe

1. Choose the CUT/SHAPE

‘Cut’ refers to the shape, style, proportions and symmetry of the diamond. The cut is arguably the most important of the four Cs. It is also the only aspect that relies solely on man, rather than nature. Only a skilled master craftsman can find the beautiful shape of a diamond within a rough stone and cut and polish it, in order to create a breathtaking effect. The sparkliest diamonds are round ones, followed by the square princess cut. Rectangular dimaonds (emerald cut) tend to give of long, sustained flashes of light, instead of sparkle. Pear and marquise cut stones are quite sparkly, although not as much as round cuts and princess cuts.

Here are 5 common diamond cuts “in order of sparkliness”:

Diamond Buying Guide: Looking Through the Jeweller’s Loupe

OUR RECOMMENDATION: We simply choose to use a Good/Very Good cut or above, in all our diamonds, to make diamond buying more straightforward for our clients.

Things to remember about CUT:
* It’s very important, because the allure of a diamond comes from the way it sparkles.
* A poorly cut stone results in a lack of brilliance and fire.


All diamonds are also graded by colour. This may sound confusing as diamonds are transparent. However, a very poor quality diamond will actually look quite yellowish. So that’s why diamonds are judged on a colour scale, from D to Z. The best colour grade is D, because it’s colourless. The worst is Z, as it’s very yellow.

Here you can see one of our “E” colour-graded diamonds. It is essentially considered colourless. It is also at the top of the price range:

Diamond Buying Guide: Looking Through the Jeweller’s Loupe

1-carat diamond in colour grade E – click on the ring to learn more

To compare, let’s take a look at this colour H diamond:

Diamond Buying Guide: Looking Through the Jeweller’s Loupe

0.50 carat Canadian diamond in H colour – click on the ring to learn more

OUR RECOMMEDATION: If you’re unsure, remember that colour H is a great colour grade to go for. Why? Because H is still in the white colour range, and the naked eye cannot tell if there is any yellow in it. You’d need to be a jeweller comparing individual diamonds under laboratory conditions and lighting, against a white background, to be able to tell. Colour H diamond are very affordable and look beautiful – that’s why they are the most popular commercial diamond colour.

Things to remember about COLOUR:
* Most diamonds have traces of yellow, brown or grey.
* The colour of a diamond is determined in a laboratory using visual assessment.
* From colour H onwards the naked eye cannot tell the colour of the stone, so it’s a safe, beautiful and affordable colour to go for

3. Check CLARITY

Clarity is an indication of a diamond’s purity. The clearer the diamond is, the more vivid and intense the sparkle will be. In most diamonds there are small mineral flecks or fractures inside. These are naturally occurring marks, called “inclusions”. The clearer a diamond is on the inside, the rarer and more expensive it is. Diamonds are measured with the below units, with “IF” (flawless) being the clearest and “I3” (inclusions) the least clear.

Diamond Buying Guide: Looking Through the Jeweller’s LoupeOUR RECOMMENDATION: We only sell diamonds with clarity grades ranging from VS1 (very slight inclusions) to SI2 (some inclusions) upwards in our E to H colour diamonds, because these clarity grades look excellent to the naked eye – and you could only see any imperfections with a jeweller’s powerful magnifying loupe.

Things to remember about CLARITY:
* Almost all diamonds have imperfections, scratches or air bubbles
* But if you choose a stone thats 1 carat or less, with slight or very slight inclusions, these will be invisible to the naked eye

Diamond Buying Guide: Looking Through the Jeweller’s Loupe

A 1 carat prince cut diamond on the hand


A diamond’s weight is measured in carats. In other words, this determines how big your diamond is.

There are 100 points to each carat. Meaning, that if a diamond weighs 50 points it will be half a carat, and this would be indicated as 0.50CT. Above, you can see how a 1.00CT weight diamond looks on a woman’s hand.

OUR RECOMMENDATION: *If you’re shopping at a reputable jewellers, have money left in your budget, and your fiancée wants a big solitaire stone, go for a H/Si colour clarity combination for any size up to 1 carat – spending the remainder of your budget on size to give her a bigger ring.

Things to remember about CARAT weight:
*Just be wary if you see a really big diamond that seems too cheap. It’s probably too good to be true. Remember, bigger isn’t always better. A badly cut, cloudy 2-carat diamond won’t be as stunning as a well cut, clear 0.50-carat stone.


“THE ‘FIFTH AND SIXTH Cs” – Certificates and Conflict-free

We additionally like to remind our customers about “a further two Cs”. Our solitaire diamonds, such as those found on many engagement rings, come with a certificate from a diamond laboratory. For example, Canadian Diamond Certification, or a laboratory analysis by the International Gemmological Institute. This type of certificate does not make your diamond’s quality or characteristics any better, but it’s independent proof of your stone’s quality and size.

Another consideration is making sure you buy a conflict-free diamond. These are stones that have been sourced ethically. They haven’t been sold on the black market by illegal groups or terrorists who commit human right violations. Read our Ethical Diamonds blog post to learn more.

Diamond Buying Guide: Looking Through the Jeweller’s Loupe

A diamond certificate issued by IGI laboratory, showing The Four Cs


Even when you’re convinced the diamond has passed the 4 Cs assessment, there is one more very important thing to consider… who is the diamond for? If you’re buying a diamond as a gift, it’s a good idea to make sure the person will like what you’ve chosen. Especially if you’re buying something like an engagement ring. Visit our comprehensive Engagement Ring Learning Centre to find out more.

Not feeling confident? Just get in touch with us. We are always happy to chat about our diamond jewellery and help you find the best one for you, whatever your style or budget.

See all our engagement rings at TheDiamondStore.co.uk.

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Diamond Buying Guide: Looking Through the Jeweller’s Loupe Diamond Buying Guide: Looking Through the Jeweller’s Loupe

Source: Internet


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