• CUT AND SHAPE

• CARAT

• COLOUR

• CLARITY

• CERTIFICATION

• OTHER DIAMONDS AND CRYSTALS

• MAINTENANCE

CUT AND SHAPE

CUT AND SHAPE

The cut refers to the shape of the diamond, based on the angles and proportions that allow light to reflect from one facet to another. Diamond shapes are many and varied, ranging from round cuts and hearts to pear and oval. The traditional shape is round brilliant with 58 facets as its symmetry allows it to reflect more light, making it the most brilliant of all the shapes. The famous Tiffany diamond was given 90 facets, 32 more than the traditional round brilliant cut, giving the Tiffany diamond intense colour and brilliance. Other popular shapes are marquise, emerald and princess.

Diamonds are known for their brilliance and a well-cut diamond should maximise this effect, whether it’s solitaire (a jewel set by itself) or in a gold or platinum setting. The cut of a diamond consists of three factors: grade, depth and polish.

• Grade - A standard grading report describes the cut of a diamond, based on the shape or outline and the pattern made by the facet arrangement (also known as the cutting style).

• Depth – This refers to how deep the stone has been cut. If a stone has been cut too shallow or too deep, the diamond will lose light through the bottom or sides, which will cause the stone to sparkle less. 

• Polish – The polish determines the stone’s brilliance. A poor polish or rough facets will reduce the diamond’s brilliance and its value.

CARAT

CARAT

1 carat = 100 points = 200 milligrams (one fifth of a gram)

The cut and setting can often make a diamond look bigger than its carat weight so examine all 4 standard measurements before buying. Large diamonds are quite rare and naturally, prices increase significantly with the carat weight. If you want a high carat diamond, often the case when buying an engagement ring, consider a slight downgrade in size.

COLOUR

COLOUR

All diamonds possess trace amounts of yellow or brown – the most valuable diamonds tend to be the colourless diamonds. However, very deeply coloured diamonds, such as a brilliant canary yellow diamond, can actually cost more than a colourless stone. These ‘fancy diamonds’ (also called Z+ diamonds) are even rarer than their colourless counterparts, and can also be found in blue, green, black, red and pink. The most famous fancy diamond is the deep yellow Tiffany diamond. Another famous gem is the Millennium diamond, the world’s largest 'D colour' diamond for its virtual flawlessness.

The chart below explains the grading of diamond colours from D to Z. Colourless diamonds are graded D and are very rare. The colour of a diamond can affect the setting in engagement rings. White colours are often set in white gold or platinum while the warmer tones are often set yellow gold.

CLARITY

CLARITY

The majority of diamonds have inclusions (small mineral traces or flaws), which are often undetectable to the naked eye and devalue the stone. The number of inclusions, their size and where they are located on the diamond can also affect the flow of light through a diamond, which reduces the brilliance. Flawless diamonds are uncommon and therefore very expensive. However, many inclusions can be concealed by a setting, which is frequently used for diamond rings.

eBay sellers often describe the clarity of larger, solitaire diamonds by referring to the industry letter grading scale. Diamonds with inclusions visible to the naked eye have a grading of I1 - I3. Small inclusions have a grading of SI1 - SI2 while diamonds with very small inclusions have a grading of VS1 - VS2. Diamonds with even tinier inclusions are graded VVS1 - VVS2 while rare diamonds with no inclusions are either known as flawless (FL) or internally flawless (IF). The International Gemological Institute (IGI) uses the grading scale below for clarity.

CERTIFICATION

CERTIFICATION

Many eBay diamond sellers offer certificated listings that include diamond appraisal (estimated retail value) and certification value in their listings. Certification, (official documents issued by third-party gemological labs) states the details about each gem (as a minimum, a grading report of the 4 Cs - cut, carat, colour and clarity) and is independent of market value. The certification can also include:

• Certification confirming the diamond’s quality

• Proof that a diamond is organic (natural)

• Serial number on the girdle of laser-inscribed diamonds (for certification and identification purposes)

Before you buy a diamond on eBay: 

• Ensure that the grading certificate has been issued by a reputable gemologist or gemological lab. It can be difficult to determine impartiality and stringency of unknown labs.

• Look for listings which offer a picture of the grading certificate and the serial number. Some labs offer online checking whereby you can type in the serial number and validate the lab that certificated the diamond as well as the specs. 

• Ask the seller how they confirmed the origin of the diamond so you can avoid buying a conflict diamond – gems sold to fund wars and purchase weapons. Some eBay sellers use the term ‘Kimberley Process confirmed’ – the Kimberley Process aims to certify international diamonds in order to stop this trade.

OTHER DIAMONDS AND CRYSTALS

OTHER DIAMONDS AND CRYSTALS

There are many manufactured diamonds on the market which include pink, blue and black diamonds and even colourless diamonds which have been clarity-enhanced. These are some of the enhanced stones you may come across:

• Clarity enhanced

• Colour enhanced

• Laser-drilled

• High Pressure High Temperature (HPHT)

• Chemical Vapour Deposition (CVD)

Also available are a range of diamond look-alikes:

• Cubic Zirconia

• Moissanite

• Simulated Gemstones

MAINTENANCE

MAINTENANCE

Diamonds might be the hardest naturally-occurring substance on Earth, but they need to be looked after. Diamonds, loose or otherwise, should be stored individually in soft cloth pouches to prevent the stones from hitting each other and chipping. Certain settings also offer better protection: four-prong setting, six-prong setting and low-profile channel (also known as bezel settings).

Regular Cleaning

Diamonds are renowned for their brilliance, but dust, oil from your skin and other unclean substances can reduce the stone’s sparkle. To protect your diamond ring, engagement ring and earrings, follow the tips below and remember, if the diamond is in a metal setting, treat it gently as gold can scratch.

• Clean your diamonds every now and then in soap and water. Let the jewel air-dry then polish with a soft cloth.

• Using a worn, soft-bristle toothbrush, occasionally brush the diamond to remove dirt from between the crevices.

• For more resistant blemishes, use a soft brush with a weak solution of one part ammonia and four parts water.
  

Professional Maintenance

Jewellers can also clean diamonds and gems for you, using steam or ultrasound. However, ultrasound can aggravate internal fissures or flaws so make sure the diamond’s existing clarity isn’t affected. You should also ask the jeweller to ensure the diamonds are secure in their settings to prevent the stones from falling out.