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DIamond Buying Guide

Our guide to buying your Diamond

Purchasing a diamond is an incredibly exciting and nerve racking process. With the vast amount of information now available it can be difficult to understand what everything means and what Diamond to choose. 


You may have already heard of the 4 C’s; these are the most important elements that define a Diamond and affect the overall look, feel and price of each stone. At Pugata we have put together a guide to help guide you.


But first what is a Diamond? A diamond is made from one single element – Carbon. It is formed under extremely high temperatures and pressures that exist around 100 miles beneath the earth’s surface. As the carbon is exposed to these conditions it crystallises and then transported to the surface. Once it has been mined, it is then passed on to a experienced diamond cutter who proceeds to turn the rough gem into the magnificent piece we know and love. 

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diamond cut

This in essence is how well the stone is proportioned and how well the position of the facets have been placed on the diamond. When light passes through a diamond, it is returned back to our eye and we see a range of different things.

The most important are:

  • Brilliance – The white light that we see when looking at a polished diamond face up.

  • Fire – The coloured light that we see when looking at a polished diamond face up.

  • Scintillation – The overall appearance of light when the diamond, light or we move. As well as the contrast of the Fire & Brilliance pattern which is formed when looking at a polished diamond face up.

If the diamond is cut poorly the light will pass through the stone and not be refracted back to our eye. This will mean your diamond will look dull and lifeless. If however it is cut well then the light will be returned back to us and we will see the sparkle and life that we want in our Diamonds. Below is an example of how light passes through a Diamond. 


There are five different grades to the Cut of the Diamond and they are as follows:

  • Ideal or Excellent Cut – The cream of the crop in cuts, rare to find these diamonds are exceptional in quality and reflect almost all the light that enters it.

  • Very Good Cut – Almost the same amount of light is reflected as an Excellent cut but these Diamonds have a slightly better price.

  • Good Cut- This reflects most of the light, and to the untrained eye looks as beautiful as either the Very Good or Excellent cut however it is much more affordable.

  • Fair Cut– This typically reflects only a small portion of light however it is still considered to be a good quality of diamond. Fair cuts are used to maximise total carat weight over anything else and can be great value for money.

  • Poor Cut– This is where the diamond has been cut too deeply or too shallow, it loses significant amounts of light and is dramatically cheaper in price than any of the other diamond grades.

  • The shape of the stone and the final cut can affect the price you pay for a stone. If you are unsure about which shape or cut is best suited for your budget then please do not hesitate to speak to one of our Gemologist for advice on which stone to select.

Diamond Carat

The Carat is the overall weight of the diamond, One Diamond Carat is shown as 1.00ct and can be divided up into 100 points. You may have heard the term a quarter carat or a half carat, these relate to the amount of points the diamond weighs e.g. 0.25ct or ¼ carat diamond. There are special carat weights which demand a higher price, for example buying a diamond which is exactly 1.00ct can be much more expensive than buying a diamond which is identical in every way except it weighs 0.99cts.


The weight of the Diamond should not be confused with the measurements of the stone, there is a correlation and a rough estimate of weight can be gained by measuring the stone but it is not the only factor to affect the overall weight. Below is a chart which can help give examples of weight and measurement – as a rule of thumb the larger the diamond the more valuable but don’t forget the other 3 C’s can affect the price.


Please note that this chart is not to scale and can differ depending on your screen size and resolution etc. 


Diamond Colour

In this instance, Diamond Colour is the term used to describe how colourless the Diamond is. It is not to be confused with Fancy Coloured Diamonds which are Diamonds containing other elements aside from Carbon.


Diamonds are colourless unless they have the presence of an additional trace element which can make them red, yellow, green or blue as well as many other colours – these are known as Fancy Coloured Diamonds. Colourless Diamonds are also known as White Diamonds, but why are some white and some a shade of yellow?


When a Diamond forms there can be all sorts of natural occurrences which can affect its growth, for example if the earth shifts it can change the direction that the crystal lattice structure was forming and this in turn can affect the way the light is refracted, thus making it more yellow the clear.


When we grade a Diamond for colour we use a set of Diamonds called the “Master Stones”. 


Diamond Clarity

The term Clarity is used to describe the presence or absence of inclusions within or on a Diamond. The Diamond clarity can have a huge effect on not only the look of the Diamond but also the price and is crucial when choosing your diamond.


Inclusions within a Diamond are natural imperfections which can be anything from crystals of all shapes, size and colour through to small feather like fractures and clouds. When grading these inclusions, we need to look at the factors behind them which will affect the final grade result. They are as follows:

  • The amount of inclusions.

  • The size of the inclusions.

  • The nature of the inclusions.

  • The position of the inclusions.

  • The colour of the inclusions.

Each factor is examined under 10x magnification and assessed to give the appropriate grade. The categories listed below can affect the look and price of your piece:

  • FL-IF = Flawless or Internally Flawless. No internal inclusions.

  • VVs1-VVs2 = Very Very Slightly Inclusions. Very difficult to detect under 10x magnification.

  • Vs1-Vs2 = Very Slight Inclusions. Can be seen under 10x magnification and in some cases the naked eye.

  • Si1-Si2 = Slightly Included. Can be seen under 10x magnification and can be seen with the naked eye.

  • I1, I2 & I3 = Imperfect. Inclusions are very clearly visible under 10x magnification and with the naked eye. 


The most expensive diamonds fall into the top 3 categories, but it can be very difficult for the untrained eye to tell the difference between the top 4 categories. At Pugata we only use Diamonds from FL – Si1 with our standard Diamonds being between Vs1-Si1. The diamond clarity can affect the price so if you have a budget then please do not hesitate to speak to one of our Gemologist for advice on which stone to select.

The 5’th C - Certification

Having gone through the 4 main important points to look at when buying a Diamond, you will be ready to buy your dream piece. There is however one last thing to take into consideration when purchasing a diamond and that is Certification.


A Certificate is a document which lists all the important parts of the diamond in an easy to read manner. There are many Diamond grading houses around the world but the most trusted and widely used are the Gemological Institute of America (GIA) for mined/natural diamonds and the International Gemological Institute (IGI) for lab grown/ethical diamonds. These organisations protect buyers and sellers of diamonds by establishing and maintaining high and consistent standards for grading Diamonds. 


Below is an example of a GIA Certificate.


GIA & IGI certificates cannot to be replaced if lost, stolen or damaged. However if you have a record of your GIA or IGI number you will be able to view and download a PDF copy from their websites free of charge.

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