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Jack Conner Designs Ltd - Your Personal Jeweller

Diamond Education

No gem is as rare, precious, beautiful and steeped in history as a diamond. The tradition of a man giving a diamond ring as a promise of marriage dates back to 1477 when Archduke Maximilian of Austria gave his beloved Mary of Burgundy a gold ring set with a diamond as a token of love.

This tradition has grown over the centuries. Today, a diamond is considered the ultimate symbol of love. Every diamond you see has undergone an amazing journey. The diamonds that are used in jewellery were formed millions of years ago from carbon deposits in intense heat and pressure deep under the earth. From here they were carried by powerful lava flows to the earth’s surface. All this time later, they are mined and polished into the exquisite gem that forms the centrepiece of our most treasured jewellery. Only half of the diamonds mined today are bigger than a match head and of gem quality. It’s no wonder that diamonds are considered so precious and magical.

Buying a diamond or a piece of diamond jewellery is therefore a significant purchase - emotionally and financially. We want you to be confident you’ve made the right choice so that’s why we’ve produced this section. Read on and you’ll learn about the 4Cs and some of the different diamond shapes available. And if you need further guidance, just contact your Personal Jeweller and we’ll be happy to help.

Understanding the 4Cs – cut, colour, clarity and carat weight. This is the key behind choosing the diamond that’s right for you.

The interplay of the 4Cs determines the value, rarity and beauty of every diamond. Once you’ve understood these characteristics, you’ll be able to consider the importance of each one to you and find the perfect diamond for your budget. It’s not complicated. For example, you might prefer a diamond with a larger carat weight and a good cut but with poorer clarity and a lower grade colour. It’s about getting the balance that works for you.

Often confused with the shape of a diamond, diamond cut refers to the angles and proportions created when transforming a diamond from a rough stone into a polished gem. It is the only one of the 4Cs not created by nature.

Put simply, cut determines the brilliance of a diamond. Diamond cutting is a highly skilled art – one which dates back to the middle ages – and is designed to bring out the very best in a diamond. The skilled craftsman polishes tiny facets into the rough diamond to create what is known as the table, crown, girdle, pavilion and culet. The skill lies in the creating the right proportion, relationships and angles of the facets.

A well-cut diamond will make good use of light, allowing it to be dispersed and reflected from one facet to another. The diamond’s brilliance and fire will be released. If a diamond is cut too shallow, light escapes from the side or the underneath and the display of light will be less brilliant. A diamond that is cut too deeply will allow light to escape through its sides and will appear less brilliant. Therefore a well-cut diamond is more valuable than one that is poorly cut.

Diamond colour refers to the degree to which a diamond is colourless, or white. The closer a diamond is to having no colour, the more valuable it is. This is because lack of colour allows the diamond to display greater fire and scintillation.

While many diamonds appear colourless, most contain shades of yellow or brown. This comes from trace elements such as nitrogen. Colour differences are very subtle and can be hard to see unless you compare diamonds of different colours side by side.

At Jack Conner Designs, we use the GIA (Gemological Institute of America) scale of colour. The scale begins at D, referring to diamonds that are truly colourless, and goes through to Z, referring to diamonds that are slightly brown in colour.

Diamonds can also be found in what we call ‘fancy’ colours. Natural coloured diamonds are formed in the same way as white diamonds with the only difference being the colour of the crystal. The colour is believed to have occurred in the forming of the crystal millions of years ago by elements being trapped in the crystal lattice. ‘Fancy’ coloured diamonds come in all shades, including yellow, brown, pink, blue and green, and are incredibly rare, valuable and sought-after.

Most diamonds contain inclusions – natural characteristics which are formed by minerals or fractures. Known as nature’s fingerprints, they may look like small crystals, feathers or clouds. Inclusions are ranked on a scale of perfection called clarity. The fewer inclusions in a diamond, the greater the diamond’s clarity and value. Inclusions can affect a diamond’s brilliance as they can block its flow of light – the light reflected in and refracted out of the stone.

Most inclusions aren’t visible to the naked eye. Clarity scales use a magnifying glass called a loupe which allows jewellers to see diamonds and the visibility of inclusions at ten times their actual size.

The most commonly used clarity scale has been developed by the GIA (the Gemological Institute of America). This starts grading as Flawless or Internally Flawless (FL/IF). Flawless diamonds have no inclusions and are extremely rare and valuable. Diamonds that are very very slightly included are graded as VVS1 and VVS2 and have inclusions that are hard to see even under a loupe. This scale continues through very slightly included (VS1 and VS2), slightly included (S1 and S2) to included ( I1, I2 and I3).

Included diamonds have inclusions that are visible to the naked eye. Inclusions can often be hidden by a diamond’s setting and therefore have little effect on its beauty.

Carat is the C that people are most familiar with and is a measure of a diamond’s weight. A diamond’s carat weight does not accurately reflect its size. One diamond may look bigger than another but have a lower carat weight. A good diamond cut can make the diamond appear larger, as can a clever setting. The carat weight has a great impact on the value of a diamond. Larger carat diamonds are found less frequently in nature so are worth more. However, two diamonds with the same carat weight can have very different prices depending on their cut, clarity and colour.

The word carat is derived from carob; in ancient times gemstones were measured using the weight of a carob seed. One carat is equivalent to a fifth of a gram. A carat is divided into 100 points, i.e. a half carat diamond weighs the same as a 50 point diamond. The point system tends to be used for diamonds under a fifth carat. It’s also important to note here that if a piece of jewellery contains more than one diamond, the carat weight stated refers to their combined weight.

Carat is often considered the most important of the 4Cs when choosing a diamond, particularly if you’re buying a diamond engagement ring. Lowering the colour and the clarity can help you get a larger carat weight for your budget.

Diamond shape is key to choosing a piece of diamond jewellery - everyone has their favourite diamond shape. Often confused with diamond cut, diamond shape refers to the appearance of the stone’s outline. The shape that a diamond is carved into is usually dependant on the rough stone. A skilled diamond cutter will consider the shape of the original stone, the location of inclusions and preservation of carat weight in order to create a diamond with maximum beauty.

The classic diamond shape that remains the most popular for diamond engagement rings.

The classic diamond shape that remains the most popular for diamond engagement rings. The round brilliant diamond was introduced in the 17th century and had just 17 facets. Over the past century, diamond cutters have used advanced mathematical calculations and light theories to create a round brilliant diamond with 58 facets for optimum brilliance and fire. A round brilliant diamond is cut to resemble a cone with a round top. A symmetrical diamond, it can return almost all the light that enters it and is therefore the most brilliant of all diamond shapes.

Any diamond shape that isn’t round is known as a ‘fancy’ diamond shape. There are many ‘fancy’ shapes but here we discuss some of the most popular ones.

The princess cut diamond has a square outline with pointed corners

A relatively new diamond shape, developed in the 1970s. The princess cut diamond has a square outline with pointed corners; its overall shape is a pyramid. It has a modified brilliant cut which accentuates the diamond’s fire and brilliance. The most popular ‘fancy’ diamond shape and a contemporary alternative to the round brilliant diamond.

The emerald cut was originally used for the cutting of emeralds but was found to work beautifully for diamonds

The emerald cut was originally used for the cutting of emeralds but was found to work beautifully for diamonds, accentuating their lustre. Emerald cut diamonds have a rectangular shape with cropped corners and a step cut where rectangular facets are arranged parallel to its girdle. Popular in the Art Deco period, this elegant shape is enjoying a huge revival.

Baguette diamonds have a slim rectangular shape that works well as accent stones to highlight a larger diamond or gemstone

The most common type of step cut diamonds. Baguette diamonds have a slim rectangular shape that works well as accent stones to highlight a larger diamond or gemstone. They’re also popular in eternity rings, set closely together to create a big sparkling look.

Oval diamonds were developed in the 1960s by Lazare Kaplan

Oval diamonds were developed in the 1960s by Lazare Kaplan, the cousin of Marcel Tolkowsky, a mathematician involved with creating the round brilliant diamond. Like the round brilliant cut, the oval diamond has a symmetrical cut that maximises the stone’s brilliance.

An elongated diamond with pointed ends and a brilliant cut that stands alone as a beautiful solitaire or works perfectly accented by smaller stones

Said to be inspired by Marquise de Pompedour when her lover, King Louis X10, commissioned a stone to match her striking smile. The result: an elongated diamond with pointed ends and a brilliant cut that stands alone as a beautiful solitaire or works perfectly accented by smaller stones.

A pear shaped diamond has a brilliant cut and combines the shape of an oval diamond and a marquise diamond

A pear shaped diamond has a brilliant cut and combines the shape of an oval diamond and a marquise diamond. Also known as a teardrop diamond, this diamond shape is a popular centrepiece for earrings and pendants.

The heart shaped diamond is a pear shaped diamond with a cleft cut into its top

The ultimate symbol of love. The heart shaped diamond is a pear shaped diamond with a cleft cut into its top. A complex cut which requires great skill to ensure optimum brilliance, the heart shaped diamond is relatively uncommon.

The asscher cut diamond has a stepped square cut which is similar to the emerald cut

Developed in 1902 by the Asscher brothers of Holland. The asscher cut diamond has a stepped square cut which is similar to the emerald cut. Until recently, this diamond shape was rarely seen. However, since its appearance in Sex and the City and on the fingers of several red carpet celebs, this stunning cut has become increasingly fashionable and sought-after.

Radiant diamonds combine the brilliance of the round diamond, the elegance of the emerald cut diamond and the sassiness of the princess cut diamond

A versatile design that’s distinguishable by cropped corners and 70 facets. Radiant diamonds combine the brilliance of the round diamond, the elegance of the emerald cut diamond and the sassiness of the princess cut diamond. They can be square or rectangular, and were developed in the 1970s by World War II veteran Henry Gossbard.

Also known as pillow cut diamonds, cushion diamonds gained popularity over a century ago

Also known as pillow cut diamonds, cushion diamonds gained popularity over a century ago. They’re available in a square or rectangular shape, and have rounded corners and larger facets for increased brilliance.

A well-cut trilliant diamond displays an incredible brilliance

One of the more unusual diamond shapes. Developed in the 1970s in Amersdam, Trilliant diamonds have a distinctive dramatic cut that combines a brilliant and a step cut. A well-cut trilliant diamond displays an incredible brilliance. Also known as trillion diamonds, trilliant diamonds are most commonly used as accent stones in jewellery.

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