Diamonds are the hardest of all naturally-occurring materials, and the most highly-valued of all precious gemstones. They are used most notably as a form of adornment, on items such as jewellery, watches, clocks and decorative objects.
Diamonds have long been used as a valuable commodity in times of financial crisis, and they have been used as a means of storing wealth since the Renaissance Period. Today they are used as an alternative investment due to their liquidity and portability.
Diamonds are rated by four criteria, known as ‘the four Cs’; cut, clarity, colour and carat. The cut refers to the manner in which the diamond has been shaped, and is often judged the most important of the criteria by jewellers when valuing a stone.
The clarity of a diamond is judged on the number of internal imperfections, or inclusions, and is rated using a specific grading system. The colour of a diamond is similarly rated on a grading scale, but this scale is designed only to rate diamonds with faint colouring. Intensely-coloured diamonds are known as ‘Fancy Colour’ diamonds, and can be of far higher value than colourless diamonds in many cases.
A diamond’s carat is a measurement of its size, with one carat being a unit of mass equal to 200mg.
Diamonds are cut to specific mathematical guidelines of angles and length ratios in order to reflect the most light. These cuts are created using a faceting machine to create the series of small flat angular surfaces on a diamond called facets.
The dispersed light reflected from a diamond is known as its ‘fire’, and appears as a rainbow spectrum of colours. The ‘brilliance’ of a diamond is the amount of white light reflected from the top. The cut of a diamond is often considered its most important quality as it is designed specifically to enhance the ‘fire’ and the ‘brilliance’.
Cuts can vary depending on the size and shape of the diamond in its original state, along with trends in jewellery design. The ‘brilliant’ cut was developed in the 17th century and featured 17 facets on their upper half. Diamonds cut this way are known as ‘double-cut brilliants’. ‘Triple-cut brilliants’ feature 33 facets instead of 17, and ‘round brilliants’ have 58 facets. Another form of cut is the ‘fancy cut’, and can include several different shapes such as baguette, marquise, round, radiant, pear, marquise, emerald, oval, heart and princess.
A diamond’s clarity is rated on a standard grading scale set by the Gemological Institute of America (GIA):
FL - Flawless - no internal or external inclusions of any kind visible under 10x magnification to a trained eye, the most rare and expensive of all clarity grades.
IF - Internally Flawless - no internal inclusions visible under 10x magnification to a trained eye, but there may be some tiny external irregularities in the finish.
VVS-1 - Very Very Slightly Included 1 - usually just one tiny inclusion visible only to a trained eye under 10x magnification.
VVS-2 - Very Very Slightly Included 2 - tiny inclusions visible only to a trained eye under 10x magnification.
VS-1 - Very Slightly Included 1 - very small inclusions visible with 10x magnification.
VS-2 - Very Slightly Included 2 - several very small inclusions visible with 10x magnification.
SI-1 - Slightly Included 1 - small inclusions visible with 10x magnification.
SI-2 - Slightly Included 2 - several small inclusions visible with 10x magnification.
I-1 - Included 1 - flaws that are visible to the naked eye.
I-2 - Included 2 - many flaws clearly visible to the naked eye that also decrease the brilliance.
I-3 - Included 3 - many flaws clearly visible to the naked eye which decrease the brilliance and compromise the structure of the diamond, making it more easily cracked or chipped.
The colour of a diamond is also rated using a GIA grading system where D is colourless and Z is yellow:
Colourless - D, E, F
Near colourless - G, H, I, J
Faint yellow or brown - K, L, M
Very light yellow or brown - N, O, P, Q, R
Light yellow or brown - S, T, U, V, W, X, Y, Z
De Beers Millennium Jewel 11
Graff Pink diamond
Antwerp World Diamond Centre
The city of Antwerp in Belgium has been the home of diamond cutting since the 15th century, and is considered the centre of the world’s diamond trade with more than 80% of rough diamonds and 50% of polished diamonds handled in the Antwerp World Diamond Centre. Concentrated within a top security area of two square miles, it comprises more than 1,500 diamond companies, four diamond bourses, four diamond banks and 300 workshops and factories, employing 27,000 people.
The bookmarklet lets you save things you find to your collections.
Note: Make sure your bookmarks are visible.
Click and drag the Collect It button to your browser's Bookmark Bar.