Buying diamond jewellery can be a mine-field if you don’t have the right information. That’s why we feel it’s important that customers understand the facts surrounding what makes a good or bad diamond.
The 4 C’s Aren’t The Whole Story
Most people are aware when choosing a piece of jewellery that the cut, the colour and the clarity of the diamond are important, both on price and on the quality of the stone. However, most customers don’t necessarily understand that there are other, just as important factors that determine whether the diamond you’re considering buying is of a high quality and good value for money.
Firstly; a summary of the 4 C’s:
Carat - The carat is a measurement of weight and volume, first used in ancient Egypt. Abbreviated to "ct." one carat is equal to 1/5 of a gram (200 milligrams). Gem stones are measured to the nearest hundredth of a carat. and we refer to one hundredth of a carat as one ‘point’. There are 100 points per carat.
In layman's terms the carat simply denotes the size and weight of the diamond. As a general rule the larger the diamond, the more expensive it will be, in relation to it's cut, clarity and colour.
Cut - There are a variety of ways in which diamonds are cut in order to highlight a diamond's incredible qualities of reflection and refraction. Each cut alters the look and brings out it’s natural qualities in a variety of ways. Some of the most commonly used cuts are shown below.
Clarity - Diamond clarity relates to the existence of visible internal characteristics noticeable within or on the surface of the diamond. These are generally termed ‘inclusions’. Surface defects are termed ‘blemishes’. The Gemological Institute of America (GIA) grade diamond clarity from ‘Flawless’, with no visible inclusions, to pique 3. with prominent inclusions visible to the naked eye.
Colour - The colour scale is used to determine the absence of the colour yellow within a white diamond. White diamonds are graded by the GIA between D, which is the whitest grade of diamond, to Z which shows considerable colour. D coloured diamonds are rarer and therefore tend to command a higher price per carat than, for example, J coloured diamonds.
Below are a few more facts about these important diamond chracteristics.
Some of the most commonly used cuts are shown below.
The Round Brilliant-cut
The round brilliant-cut is the most widely used of all of the diamond cuts. The unique way in which it is polished and faceted makes the most of a diamond's natural qualities of reflection and refraction, with a total of 57 facets throughout the stone. This cut is considered by many to be the optimum diamond cut, reflecting enough light to demonstrate a diamond's natural brilliance.
Brilliant cut diamonds work well in any and every style of jewellery, whether on their own or with other gemstones.
The emerald-cut was first developed in the 1920’s to accentuate the colour and clarity of the diamond, rather than it's natural sparkle and 'fire'. Each corner is removed during the faceting of the stone, as these areas are most vulnerable to damage .
This practice has long been carried out when faceting emeralds, which are far softer but equally valuable. Hence the name "emerald-cut".
The oval was developed in the early 1960's. The symmetrically oval shape, with it's characteristically long sides, gives the oval-cut stone the appearance of being larger per carat than other cuts, such as the brilliant cut.
Due to the unique way in which the oval cut is faceted, when looked at from above it can display a 'bow effect' across the centre of the stone that has become characteristic of the oval-cut, as shown in the picture to the below-right.
The princess-cut was also developed in the first half of the 1960's. It is very similar to the brilliant-cut in that it has 57 facets and as a result is considered by many to be the second most popular of all diamond styles.
Like the brilliant-cut it is an extremely versatile cut. From rings to pendants, from solitaires to clusters, it works well in a wide variety of settings and jewellery types.
The chart below helps demonstrate the difference between the various grades of diamond; from 'colourless' to yellow.
The diagram below helps demonstrate the differences between the various grades of diamond clarity.
The certification of a diamond is important when buying a stone of high colour and clarity because it is proof, by impartial scientific analysis, that the quality of the diamond is as high it pertains to be.
Although many retailers offer certification of their diamonds only a handful of gem-stone testing laboratories are considered to offer trusted and authentic impartial certification, for example the Gemological Institute of America (G.I.A.).
Without a trusted certificate, from an independent laboratory of this calibre, the colour and clarity of a 'certificated' diamond cannot be guaranteed.
The United Kingdom is unique in that it has the most stringent and thorough laws in the world pertaining to the hallmarking and sale of precious metals.
Any item of jewellery made of either silver, gold, platinum or paladium that is manufacturered for sale in the U.K. jewellery industry must be independently tested by an Assay Office, to ensure that the metal alloy meets certain designated standards.
Providing the alloy meets these standards of 'fineness' the Assay Office with apply a series of hallmarks to the item of jewellery, as proof that the item is manufactured to a high enough quality to be legally sold as either gold, silver, platinum or palladium.
The 'fineness' of a precious metal alloy denotes the ratio of pure gold, silver, platinum or paladium to the amount of base metal mixed with it in order to allow that metal to be worked and worn more safelyas an item of jewellery, and without causing undue wear or damage.
Pure silver, for example, if worn as jewellery is too soft to retain its manufactured shape and will bend very easily. It must therefore be mixed with a small quantity of harder, non-precious, 'base' metal in order to give it more strength. The resulting mixture is referred to as an alloy.
There are various different alloys for gold, silver, palladium and platinum. Each must meet strict standards, set by law, in order to be sold in the United Kingdom. Each item of jewellery sold in the UK is therefore tested by an independent Assay Office. If it meets the necessary requirements it is then hallmarked and can legally be sold as a precious metal.
Below is a hallmarking chart for the standards in United Kingdom