Carat – The larger a diamond, the more rare.
Clarity – The purer a diamond, the more brilliant.
Color – The less in a diamond, the more rare.
Cut – The better cut a diamond, the more brilliant.
A Jeweller who’s a diamond expert can help you to select the right stone. Trustworthy jewelers, who establish long-standing relationship with customers, take pride in finding quality diamonds for them.
A trusted jeweller can help you choose a diamond shape that suits your personal taste. The classic Round Brilliant, Oval, Pear, Marquise, Princess, Heart and Emerald shapes are among the most beautiful and popular today .
Carat is the term used to describe the weight of any gemstone, including diamonds. Although the definition of a carat has changed over time, since 1913 the international standard has been 200 milligrams, or 1/5 of a gram. Often, jewellers describe carats in 1/4 increments.
In jewellery pieces with more than one diamond, the carats may be described in terms of total carat weight (TW). This is the combined total weight of all the stones in the piece.
Diamonds can range in size from a fraction of a carat to several carats. Given the rarity of large stones, however, the price increases rapidly with size; therefore, a single 2-carat diamond will cost much more than two 1-carat diamonds. Very large diamonds with good colour and clarity are very rare.
Because round brilliant cuts follow exact standards, you can make a good estimate of the carat weight of the diamond based on the it’s diameter. The following chart compares the relative sizes of diamonds and describes how much a round brilliant diamond of a certain size is likely to weigh. This method doesn’t work as well for other cuts or shapes, though, since some are thicker or thinner than others; nor does this chart apply to coloured gemstones, which have a different density from diamonds.
It is very common for diamonds to be formed with slight imperfections. These are known as “inclusions” and can come in many forms, including tiny white points, dark dots, or feathery cracks. The fewer inclusions, the more the stone is worth. A diamond’s clarity ranking is determined by the number, size, type and placement of the inclusions.
A stone with only a few hard-to-see pinpricks located near the edge, where they can be covered by the mounting, has better clarity than a stone with a crack located right under the table (the large top facet of the stone). Cracks from the surface to the interior are especially dangerous because the diamond could break if hit the wrong way. On the other hand, small nicks and chips on the surface are often of little concern because they can be polished away.
For the most part, diamonds used in jewellery are clean to the naked eye. In a certified diamond, the cracks are charted on the certificate and act as a fingerprint for identifying a particular stone.
The following is the GIA clarity scale, along with corresponding definitions for different clarity grades, which is very commonly used:
| DIAMOND CLARITY SCALE | |||
| FL | FLAWLESS | Free from all inclusions or blemishes at 10x magnification. |
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| IF | INTERNALLY FLAWLESS | No inclusions visible at 10x, insignificant surface blemishes. |
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| VVS1 VVS2 VS1 VS2 |
MINOR INCLUSIONS | Difficult to see face-up at 10x. | |
| SI1 SI2 |
NOTICEABLE INCLUSIONS | Easy to see at 10x. | |
| I1 I2 I3 |
OBVIOUS INCLUSIONS | Easily visible to unaided eye. | |
The following is the GIA clarity scale, along with corresponding definitions for different clarity grades, which is very commonly used:
Most diamonds appear colourless but actually have slight tones of yellow or brown. The closer the stone comes to colourless, the more valuable it is. Diamonds are graded on a colour scale ranging from D (colourless) to Z (heavily tinted.) Only a highly skilled professional will detect any colour in E or F stones, and the colour in diamonds rated up to J will be virtually invisible when set in a ring or other jewellery.
Colour is only one of the four C’s so even when a stone has a visible tint, such as K or above, it can still be very lovely if it has good clarity and cut. How the diamond is set can make a difference, too; you might not want to put a truly colourless diamond in a yellow gold setting since the yellow colour will reflect in the stone. On the other hand, a slightly yellow stone will appear whiter in a yellow gold setting.
Diamonds also come in a wide variety of other colours, including red, blue, green and a bright yellow known as “canary.” These are graded as Z+ and are known as “fancy” diamonds. Ones with good colour are very rare and can sell for much more per carat than white diamonds.
In the strictest definition of the term, “cut” is not the same thing as “shape” – for example, the most popular cut for a diamond is the round brilliant cut, but there are also round Swiss cuts, round Old European cuts, and round 100-facet cuts. For the most part, however, the terms are used interchangeably, including on this site.
The 58-facet round brilliant cut is the most popular because of its fire and brilliance. (These terms describe the intensity of the colour and brightness of the light one sees in a diamond.) This is achieved by cutting the stone to very exacting mathematically-determined proportions so as much light as possible is reflected out the top of the diamond.
The cut of a diamond refers not only to the shape of the diamond and number of facets, but also to the quality of the cut. A diamond with uneven or poorly proportioned facets won’t be given the same grade of cut as an ideally proportioned and masterfully cut stone. This information will be found on the certificate of a certified diamond.
Although most diamonds on the market today are round brilliants, there are many different shapes available. The following chart shows some of the most popular shapes:
POPULAR DIAMOND CUTS AND SHAPES
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| round | pear | heart | oval | marquise | emerald | princess |
Carat is the term used to describe the weight of any gemstone, including diamonds. Although the definition of a carat has changed over time, since 1913 the international standard has been 200 milligrams, or 1/5 of a gram. Often, jewellers describe carats in 1/4 increments.
In jewellery pieces with more than one diamond, the carats may be described in terms of total carat weight (TW). This is the combined total weight of all the stones in the piece.
Diamonds can range in size from a fraction of a carat to several carats. Given the rarity of large stones, however, the price increases rapidly with size; therefore, a single 2-carat diamond will cost much more than two 1-carat diamonds. Very large diamonds with good colour and clarity are very rare.
Expect to pay a premium for stones that are above a full carat weight. For example, a .95 carat diamond will cost a bit more than a .90 carat diamond, but a 1-carat diamond will cost significantly more than a .95 carat diamond.
Because round brilliant cuts follow exact standards, you can make a good estimate of the carat weight of the diamond based on the it’s diameter. The following chart compares the relative sizes of diamonds and describes how much a round brilliant diamond of a certain size is likely to weigh. This method doesn’t work as well for other cuts or shapes, though, since some are thicker or thinner than others; nor does this chart apply to coloured gemstones, which have a different density from diamonds.
