Diamond Education


A diamond’s colour refers to how White or yellow it is. In general, the highest quality diamonds are totally colourless, whereas lower quality diamonds can often have a slight yellow tint. We recommend selecting the Colour of your diamond based on the shape and what metal it is set in. For example, when working with a white metal such as Platinum or White gold, we recommend a D-G colour. If we were setting a diamond in Yellow or Rose Gold you can go as low as a J colour as the reflection of the metal tends to hide most traces of colour. In elongated diamonds that are shallow such as the Oval & Pear shape, we would recommend trying to stay within the D-G colour range.


Clarity in short is the natural imperfections that can be found in diamonds such as internal minor air bubbles and fine markings. As you go higher in clarity grading, the imperfections become less visible to the naked eye. Although you may not see the imperfections, if any can be seen through a 10x magnification loupe, it will be noted and graded accordingly. This is precisely how all clarity gradings come to be – using the loupe to assess the diamond from a bird’s eye view (top of the diamond). Our strongest recommendation is not to choose a clarity lower than SI2 however this does not mean that all SI2 clarity diamonds are eye clean. They can sometimes display large black inclusions which can be easily seen without a loupe. We try to avoid diamonds that have black imperfections & our general recommendation is usually FL-SI1 clarity pending our client’s specific requirements. For the best value for money, VS2-SI1 clarity is your best bet which ensures you will maintain a high-quality stone without paying for the Flawless price tag. test


Cut gradings are only for Brilliant Cut (Round) shaped diamonds. All the other shapes do not receive a cut grading on paper as there are too many variables in the measurements. Instead, they receive a Polish and a Symmetry grading. We recommend Either Excellent or Very good for these gradings. With a Brilliant Cut diamond, we would recommend what is called a Triple Excellent grading – Excellent cut, Excellent Polish and Excellent Symmetry to achieve maximum fire in the diamond.


Ultimately, the Carat is the unit of measurement for the physical weight of diamonds. To most people the Carat weight is the most crucial element when looking for that perfect size however we have a tip that could make all the difference when contemplating the size of your diamond.  If you are looking at an elongated shape such as a Pear or an Oval cut, then the measurements are even more essential than the actual Carat weight. What we mean by this is, it all depends on how the stone has been cut. In some instances, you can obtain a larger looking stone with a lower Carat weight depending on how the stone has been cut. Take a 1.20ct and 1.50ct Oval for example. If the 1.50ct is cut with a lower ratio (meaning it is wider, slightly shorter and rounded) and the 1.20ct is cut with a higher ratio (meaning longer and thinner in shape) then the 1.20ct could measure larger and look substantially bigger on the finger.


Fluorescence in a diamond is a chemical make-up when it is being formed. This can only be seen under a blue UV light and will not affect the fire or lustre of the diamond when looking at it in person. If you find a diamond with no fluorescence it will usually come with a higher price tag as it is a rarer stone. On the upside finding a diamond with some Fluorescence can help you maintain the quality you want while preserving your budget. 

The scale for fluorescence is Nil, Faint, Medium, Strong and Very Strong.

Elongated Diamond Ratio vs Carat Weight

When looking at Oval, Pear, Radiant, Emerald and Marquise shaped diamonds, the ratio is one aspect you should focus on. To find the ratio you simply take the length then divide it by the width of the diamond. This is how we maximise the overall look of the diamond without overpaying for a higher carat weight. If you would like a rounder oval, we would recommend a 1.37-1.45 ratio. If you would prefer an Elongated Oval, then head towards a 1.50-1.58 ratio. Elongated Pear shapes should be 1.60-1.70, Radiant & Emerald cuts 1.37-1.48 while Marquise should hold 1.90-2.20 ratios.

Left: 1.5 ratio pear not elongated Right: 1.7 ratio pear elongated

Natural Diamonds vs Laboratory Grown

“Natural vs Lab Grown diamonds. Which are better?” This is a common question we get asked frequently. In our opinion, we believe that the value lies in the eye of the beholder. Some clients love the fact that the Natural diamond is earth mined and is a one of a kind, whilst others are happy with a man-made product as long as it carries the identical chemical make up as a natural diamond would (without the price tag). The main difference with the two is that the Lab Grown diamond is mass produced meaning it isn’t rare and therefore it is valued at a lower price.  The Natural diamond is quite rare and will become rarer as time goes on and so it’s value will be a lot higher. Although identical in appearance to natural diamonds, Lab Grown diamonds have very subtle differences that can only be detected by trained gemologists and sophisticated equipment designed for that purpose. Michael Arthur does specialise in Natural Diamonds, but we are also able to source and supply our clients with Lab Grown diamonds.  Both Diamonds still receive Certificates upon purchasing/shipping however they might be from a different certification company.

Left: Lab grown diamond Right: Natural diamond

How your ring should fit.

We highly recommend requesting one of our M.A ring sizing kits after purchasing if you are unsure what ring size you should select. The ring should slide on well without strangling your finger. If you feel like you need to wriggle the ring with some force to remove it from the hand, that is a good sign as it would be too large if it were to slide off easily.  We do offer the first resize free if the difference is 2-3 sizes from the size it was made to upon ordering.

What does the term ‘Eye Clean’ mean?

‘Eye Clean’ is a term which is used to describe a diamond when its inclusions cannot be seen with the naked eye. We at Michael Arthur strive to only sell Eye Clean diamonds so we have added filters to our online diamond stock to try and maintain our high-grade quality. This however is not bulletproof so if there is a diamond you see that you are unsure of, please contact our team to confirm or deny if this is 100% eye clean and the best fit for you.

Left: Eye clean Right: Not eye clean

‘Milky’ Diamonds

‘Milky’ or ‘Cloudy’ diamonds usually have inclusions that make it appear hazy in some parts or all of the diamond. We do not work with any diamonds that are Milky or have any tinge of colour. Although it isn’t a technical grading term which is seen on the certificate, it should still play a very vital part in the selection of your diamond. So to ensure we maintain the best quality possible, we have excluded any diamonds that contain a Milky, Cloudy or coloured tinge in our inventory. 

Left: Milky diamond Right: Not milky diamond