Diamond Buying Guide

We have years of experience selecting and selling fine jewellery and have a long partnership with experts who only choose gems
that they are happy to put their name to. This should give customers confidence that every piece they are shown is a good product and we are happy to tell you why.

Choosing jewellery should be enjoyable and fun, come and see us, try lots on and be happy that you have found your perfect gems.


The Story of a Diamond

Diamonds have a history that stretches almost as far back as the earth itself. Formed deep underground over millions of years and through immense heat and pressure, diamonds were forced towards the earth's surface by volcanic activity. Made up of only carbon, the diamond is the purest of all precious stones. Its unparalleled strength makes it last forever, perhaps why it has been adopted as the symbol of love.

These gemstones have been surrounded by myth and legend for centuries. In Greek times it was believed that diamonds were remnants of fallen stars. Diamonds have also been connected with romance for thousands of years.
The ancient Egyptians believed that you should wear your diamond on the third finger of your left hand, which contains the 'vena amoris' (vein of love), which flows directly to the heart.


Choosing a Diamond

Buying a diamond should be based on the right knowledge, as they come in many qualities.  The four C’s – Clarity, Cut, Carat and Colour – are used worldwide to describe the quality of diamonds. The rarest and most valuable diamonds are those that are the clearest and purest.

Other factors that determine a diamond’s quality and value are its symmetry and cut. Learning as much as possible about the differences in quality and value will help you choose the right diamond. If you have any queries, feel free to ask one of our expert staff.


Diamond Cut

Cutting a diamond properly shows off its brilliance. A master cutter ensures full light dispersion, maximising the inherent beauty of the stone.

The ‘cut’ of a diamond does not refer to the shape of the stone, but rather the process of transforming the rough diamond into the finished gem. It is the only one of the 4 C’s that is influenced by hand, rather than nature.

Diamonds are revered for their ability to transmit light to create a sparkle. The proportions of the facets of the diamond are carefully calculated to ensure the face up appearance of the diamond is as desirable as possible. When a diamond is cut to the right proportions, light is refracted internally from one facet to another before being dispersed through the top of the stone.

If the cut is too deep, some light will escape through the opposite side of the pavilion; too shallow and light will escape through the pavilion before it can be refracted. A master cutter ensures full light dispersion, maximising the inherent beauty of the stone.

When a diamond is perfectly cut, the light rays enter the diamond and are bent towards the centre and then reflected back through the top of the stone. If a diamond is cut too deep or too shallow, the light can be lost through the sides or base of the stone which results in a dull or dark stone.

Diamond Clarity

The Gemological Institute of America (GIA) has developed a universally acknowledged scale for grading the clarity of diamonds that has become an industry standard throughout the world. This universal language of diamond grading ensures
protection for both the retailer and customer by identifying a system and standard that all jewellery industry professionals should adhere to. 

A diamond has the capability to refract more light than any other gemstone. One which is free of interior inclusions or exterior flaws has nothing to interfere with the passage of light through the stone and so is considered to be of the highest quality. Such stones are very rare and correspondingly expensive!

Most diamonds contain tiny natural marks called inclusions. The number of inclusions, their size and location all affect the diamond’s clarity grade. While it is true that the clearer a diamond, the better, minor inclusions will not compromise a stone’s beauty or endanger its durability.


Diamond Colour

The best colour for a diamond is no colour at all. These are known as ‘white diamonds’. Other rare diamonds with a pure colour, such as pinks, blues or greens, are also valuable and are known as ‘Fancies’.

Colour grading scales from colourless to light yellow. The differences from one grade to another are very subtle, evidenced by the number of grades within each category shown on the International Colour Grading Systems Chart.

Diamonds range from colourless - the rarest and most valuable - to yellowish, with a spectrum of shading in between.

Leonard Dews only accepts diamonds in the 'colourless' and 'near colourless' rabnge on a diamond colour scale. 


Leonard Dews only offer diamonds that have been graded from I and above, so you can be assured that your selection will be a quality gemstone.