Diamond Education


Buying Jewellery

Buying an item of jewellery, whether it be an engagement ring or gift for someone special, should be a pleasurable experience in one’s life, yet on some occasions it can appear to be somewhat daunting, not only with regards to choosing the right piece, but also in understanding all about the item you have chosen. At Lambton’s, our team take pleasure in guiding you throughout the process of finding that special piece of jewellery to suit your requirements. If you are looking to purchase an item of jewellery, and require any guidance, or have any queries, please feel free to contact us, or visit our shop, and we will be delighted to assist you.

Understanding Diamonds – The Four C’s

When purchasing a diamond, it is useful and important to understand what is known as the Four C’s. It is a universal method, used within the jewellery trade throughout the world, to assess a diamonds quality. By using this standard, it means that a diamond’s quality can be communicated in a universal language, and from a consumer perspective, it can help you to understand what you are purchasing, as the value, rarity and beauty of a diamond are determined by four factors, which are now commonly known as the four C’s. These factors are: Colour, Clarity, Cut and Carat.


The colour evaluation of a gem quality diamond is based upon the absence of colour. The purest of diamonds have no hue, and are completely colourless. Diamond colour is graded on a scale of D to Z, D being colourless, through to Z, where you will see a gradual increase saturation of light yellow colour throughout the stone. These colour distinctions are so subtle they can be invisible to the untrained eye.


The clarity evaluation of a gem quality diamond is based upon the absence of Inclusions and Blemishes in the stone. A natural diamond is the result of carbon that has crystallised, deep within the earth’s mantle, at extremely high pressures and temperatures, many millions of years ago. As a result of this natural process, during the formation stage of the diamond, it often resulted in a variety of inclusions and blemishes being left within the stone, inclusions being internal characteristics and blemishes external characteristics. The fewer inclusions / blemishes a diamond has, the greater the clarity grade will be, but it is important to understand that it is very common for diamonds to have natural flaws to varying degrees, and perfect diamonds with regards to clarity, those with no flaws at all, are extremely rare. A diamond’s clarity is graded on a scale of Flawless to Included 3.


The cut evaluation of a gem quality diamond relates to the stone’s ability to transmit light and sparkle intensely, which is achieved through how well a diamonds facets interact with light. The cut of a diamond is based upon how the stone is fashioned during its cutting process, in order for the stone to deliver a maximum return of light, where the light is reflected and dispersed from one facet to another, releasing the diamonds brilliance. A diamonds cut grade is evaluated in terms of its quality of cut, which encompasses three elements, Proportions, Symmetry and Polish. These three elements are graded on a five tier grade scale, from Excellent to Poor.

(Note: The cut of a diamond is often mistaken for its shape and cutting style, i.e. Round Brilliant Cut, Princess Cut, Emerald Cut, Pear Cut, Marquise Cut, Heart Cut, Oval Cut and Cushion Cut etc).


The carat evaluation of a diamond relates to the measurement of the diamonds weight, not its physical size. A carat is split into 100 points, where 100 points is equal to one carat. (I.e. A half carat diamond  = 50 points or 0.50ct). All other factors being equal, (Colour, Clarity and Cut), a diamonds price will increase with its carat weight, as larger stones are rarer.

Shape and Cutting Style

The shape and cutting style of a gem quality diamond relates to its physical shape, the most popular of which is the Round Brilliant Cut. However, there are many other shapes available, which are more popularly known as Fancy Cuts, which include but are not limited to, Princess Cut, Emerald Cut, Pear Cut, Marquise Cut, Heart Cut, Oval Cut and Cushion Cut etc. Choosing the shape of a diamond is purely based on personal taste and preference.

Buying your Diamond 

At Lambton’s, we have an extensive selection of diamonds and diamond set jewellery for you to choose from, of various shapes, sizes and qualities. Please feel free to contact us with any enquiries you may have, or visit our shop, where one of our team will be delighted to show you a selection of different stones, and guide you through the elements of the Four C’s, to assist you in sourcing the most suitable diamond for your requirements and budget.