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What is a diamond?

A diamond is a crystal made of carbon atoms arranged in an isometric or cubic matrix. A cubic crystal arrangement expands outward in all directions at the same rate during its initial growth; the ideal result, when the crystal forms without any interference, is a pure and perfectly formed octahedral shape. Most diamond crystals, though, face varying heat or pressure, other elements, or even other diamond crystals during their growth, which changes their form. The resulting form and characteristics of the crystal, once it emerges from the earth, help to determine what shape, colour and clarity the polished gem will have.

The combination of diamond's molecular composition and its crystal structure is what makes it so unique and gives it all the qualities that we think of when we think of a diamond.

Diamond's unique characteristics go far beyond what you can see with your eye: they're not just beautiful, they are the hardest natural substance on earth.

Diamonds do not easily break, chip or crack, and they are extremely resistant to heat and chemicals: it would take a temperature of at least 720° Celsius in air, or 850° Celsius in a vacuum, to burn a diamond; and sulphuric and hydrochloric acids, which are capable of completely dissolving the skin and bones of a person, have no effect at all on diamonds (in fact, these acids are actually used to clean the oil and dust off polished diamonds after they have been cut).


How are diamonds formed?

Over millions and millions of years, around 90 miles (150km) below the Earth's crust, diamonds are formed from pure carbon by incredible pressure and temperatures of 2,000° Fahrenheit (1,100° Celsius).

This piece of carbon adventures through molten lava flows, over billions of years to the earth's surface. By the time they find their way on to our fingers and necklaces, some diamonds are over three billion years old - not much younger than the Earth itself.


Where do diamonds come from?

Natural diamonds are mined in 25 countries across five continents, but Africa, Russia, and Canada dominate world's natural-gem quality-diamond production, and 50% of diamond mining is done in Africa.


Do you sell conflict diamonds?

In a word, no. And we never will.

Conflict diamonds are diamonds that come from countries or areas controlled by illegitimate forces, who use their diamond resources to fund military action against internationally recognised governments.

Our policy on conflict diamonds is absolute. We will not buy, sell or handle any diamonds of unclear provenance. We only source diamonds from suppliers who adhere to the Kimberley Process.


What is the Kimberley Process?

In 2003, the Kimberley Process Certification Scheme (KPCS) was set up to stop conflict diamonds joining the mainstream rough-diamond market, and 'to ensure that diamond purchases were not financing violence by rebel movements and their allies seeking to undermine legitimate governments'.

The World Diamond Council put together the System of Warranties for diamonds, which all KPCS participants endorsed, stating that all buyers and sellers of both rough and polished diamonds must make the following affirmative statement on all invoices:

'The diamonds herein invoiced have been purchased from legitimate sources not involved in funding conflict and in compliance with United Nations resolutions. The seller hereby guarantees that these diamonds are conflict free, based on personal knowledge and/or written guarantees provided by the supplier of these diamonds.'

Warranty declarations are only permitted on sales invoices with corroborated warranty invoices received for purchases. Any company that sells diamonds keeps records of all warranty invoices of diamonds coming in and going out, which are audited yearly by the company's auditors.



As part of the diamond industry, Marmalade has joined others in adhering to self-regulated principles we believe necessary to stop the use of conflict diamonds:

  • to only work with companies that have warranty declarations on their invoices;
  • to only use reliable sources that deal with countries known to use the Kimberley Process Certification Scheme;
  • to not buy diamonds from any sources that, after a legally binding due-process system, have been found to have violated government regulations restricting the trade in conflict diamonds;
  • to not buy diamonds in or from any region that is subject to an advisory by a governmental authority indicating that conflict diamonds are emanating from or available for sale in such region, unless diamonds have been exported from such region in compliance with the Kimberley Process Certification Scheme;
  • to not knowingly buy or sell or assist others to buy or sell conflict diamonds;
  • to educate all employees in trade resolution and government regulations restricting the trade in conflict diamond

Understanding the Basics of the Four Cs of Diamond Quality

Now we have all of the slightly formal stuff out of the way, let's get down to the pretty part of diamonds. This is why we love diamonds, right here.

At Marmalade, we do enjoy a good chat about diamonds and, honestly, we can get a bit geeky about it. Our heart is in the right place though: all we want is for you to feel confident in what you buy. Every diamond is unique, you know that, but what makes them unique? And how will those diamond personalities affect the price of your diamond? Questions, questions. Here we have answers, answers.

The Four Cs have your answers, actually. Cut, colour, clarity and carat weight. Focus on the elements of diamond that are most important to you, and choose a diamond that satisfies your unique standards for beauty and value. This might be a very different diamond than someone else with a similar budget would choose.



It´s the cut that gives your diamond its sparkle, its brilliance. To glimmer beautifully, a diamond should have an Ideal, Very Good or Good cut – the ones we stock, of course; a poorly cut diamond looks dull, even if it has the perfect colour and clarity – we don´t stock them. Sparkle, would you believe it, is actually measurable! It´s all about how a diamond reflects light: when a diamond is cut with the proper proportions, light bounces out of the top of the diamond (which gemmologists refer to as the table). If it is cut too shallow, light leaks out of the bottom; too deep and it slops out of the side.



There are all sorts of fancy, natural-coloured diamonds, but in the 4Cs, oddly, colour refers only to white diamonds, which range in colour from a pale yellow or cognac refers to completely colourless as far as the eye is concerned.

The less colour a diamond has, the higher its colour grade. Colour, for many, is right up there after cut because after the eye has been drawn by the sparkle (from the cut), the colour is the next thing it sees.

A colour grade of D is the highest possible, while Z is the lowest.

Top of the pops is the colourless white diamond, and it´ll cost you a pretty penny. For a colourless white diamond, look in the D-H colour bands.



Clarity is the measure of the teeny flaws found in almost all diamonds. Just like humans, diamonds free of internal flaws, or inclusions, are extremely rare and highly-valued. If your eye can´t see any flaws, then you can be very happy with your diamond.

Most flaws can only be seen under a microscope and really don´t stop a diamond from being beautiful, but thosewith the least and smallest imperfections receive the highest clarity grades.

Gemmologists refer to diamonds´ imperfections by a variety of technical names, including blemishes and inclusions.



FL, IF Flawless, Internally Flawless: No internal or external imperfections. Internally Flawless: No internal imperfections. Very rare.
VVS1,VVS2 Very, Very Slightly Included: Very difficult to see imperfections under 10x magnification. An excellent quality diamond.
VS1,VS2 Very Slightly Included: Imperfections are not typically visible to the unaided eye. Less expensive than the VVS1 or VVS2 grades.
SI1, SI2 Slightly Included: Imperfections are visible under 10x magnification, and may be visible with the unaided eye. A good diamond value.
I1 Included:This grade of diamonds will have minor inclusions that may be visible to the unaided eye.
I2,I3 This grade of diamonds will have inclusions that will be visible to the unaided eye.

Carat Weight

Just as our own weight doesn´t tell us much about our size, a diamond´s caratweight tells you little about a diamond.

Getting hold of a small diamonds it relatively easy, but larger, heavier ones are pretty rare, which is reflected in the price.

There are a couple of elements to think about if you want to understand diamond size and carat weight:

  • Distance in millimetres across the top of the diamond.
  • Diamond's cut grade.

Most of us see diamonds from the top, from the surface visible when its set in a ring, and this is important because, of course, that´s how we most like to see diamonds, but the cut grade is what you also need to know about when you´re choosing a diamond.

With a good cut, a diamond sparkles because of the amount of light its able to reflect. Lots of sparkle makes the diamond look bigger, which is always a bonus.

On the flip side, a badly cut diamond might be quite heavy even when the top appears small – all of the weight is hidden down below.



Ultimately, it´s entirely possible to have a diamond of a lower carat weight and higher cut grade that appears larger than a diamond with a larger carat weight, but poor cut. Capiche?

Much as there are 100 pence in a pound, a one-carat diamond is 100 points, so 50 points is half a carat. And so the maths goes on.

Right. We´re 4Cs down, and knowing them should put you on track to working out the last one: cost.


Choose Your Diamond Size

See the chart below to get an idea of the sizes of round diamonds.


Is a diamond a good investment?

Do you want the romance or the logic? We´ll go logic first, then the waxing lyrical can begin.

Diamond prices have been steadily increasing for the past 20 years, and diamonds tend to hold their value. It´s pretty unlikely diamonds are ever going to lose their value because of the esteem society holds them in. But we all know how unpredictable life can be, so buying up high-quality diamonds as the main part of a financial/retirement plan might not be the best idea. Just in case.

The waxing lyrical bit: OF COURSE. Diamonds are beautiful; they´re the most resilient rock on the planet and are an enduring symbol of eternal, everlasting love. Sigh. There is little in life more perfect: a smile, a baby´s laugh, maybe, but a diamond really is forever.

As a timeless treat to yourself or as an emblem of your deepest, most resilient commitment to another, a diamond really is an excellent investment.


What is a diamond certificate?

It´s a passport, an independent-laboratory´s report that grades the diamond´s 4Cs, usually, these days, with a fairly detailed description of a diamond´s cut grade.

Most of Marmalade´s engagement rings have an individual certificate for the main diamond. The most common certificates we use at Marmalade are GIA, IGI and HRD because they provide the best, most consistent results.


What is the difference between a certified diamond and a non-certified diamond?

For the diamond, there is no difference; it´s all about the certificate. The difference between a certified and an uncertified diamond is that, with the certified diamond, you have tangible independent assurances about the nature and quality of the diamond you are purchasing.

An uncertified diamond is not necessarily a bad diamond, and it certainly can be as beautiful as a certified one, but it lacks the steps in its creation that adds to a premium price.

Really it boils down to consumer confidence and how confident you feel with us. All Marmalade team members have gemmology qualifications and diamond grading training. You can be completely confident that when we grade a non-certified diamond that it is what we say it is.


Is it important to buy a certified diamond?

Marmalade uses certified diamonds in our stock engagement rings but the rest of our stock will come with a Marmalade certificate, which will accurately specify the diamond quality and size in your jewellery, for your insurance. A certified diamond isn´t vital when you trust your jeweller.


Can I specify that I would like the diamond to be graded by a specific lab?

Yes, of course. Just get in touch and we can arrange the grading at the lab of your choice for the diamond of your dreams.


Famous Diamonds

The Great Star of Africa

The largest cut diamond in the world weighs in at 530.20 carats. The Cullinan I or Star Africa diamond was cut fromthe largest diamond crystal ever found,the 3,106-carat Cullinan, which was found inTransvaal, South Africa in l095. Some believe that there is a second half to the original crystal, but it´s not shown up yet!

The diamond, cut by Joseph Asscher and Company of Amsterdam,and now set in the Royal Sceptre (kept with the other Crown Jewels in the Tower of London), ispear shaped, with 74 facets. For around six months, the cutters examined the enormous crystal before deciding how to divide it. Ultimately, it yielded nine major and 96 smaller brilliant cut stones.

The Orloff

What a history this one has! This exceptionally pure, slightly bluish green 300-carat crystalwas found in India. Now mogul-cut rose, this gem currently rests in the Diamond Treasury of Russia in Moscow.



Rumour has it that it may once have been set as the diamond eye of Vishnu's idol (one of the Hindu Gods) in the innermost sanctuary temple in Sriangam, before being stolen in the 1700s by a French deserter. Apparently, the deserter was so terrified at the thought of retribution that hejust dug one eye from its socket, but he just wanted it gone, so he hurtled too Madras, where sold the stone quickly to an English sea-captain for £2,000.

Over time, the stone arrived in Amsterdam, where the Russian Count Grigori Orloff, an ex-lover of Empress Catherine the Great lived. After hearing rumours of the stone, he hunted it down and bought it for £90,000 as a gift for his ex-lover, Catherine. Accepting the gift, Catherine had it mounted in the Imperial Sceptre and gave a marble palace to Grigori in exchange for the Orloff, the name it now carries. Poor old Grigori, though, didn´t win Catherineback and lived a miserable life in his marble palace until he died in 1783.

In 1812, the Russians, fearing that Napoleon with his Grand Army was about to enter Moscow, hid the Orloff in a priest's tomb. Napoleon supposedly discovered the Orloff's location and went to claim it. However, as a solider of the Army was about to touch the Orloff, a priest's ghost appeared and pronounced a terrible curse upon the army. The Emperor, Napoleon scampered away without the Orloff.



The Centenary Diamond

The 'Centenary' diamond weighed 599.10 carats in the rough and now glimmers at 273.85 carats. In July 1986, itdiscovered at the Premier Mine, the same mine the Cullinan was found in.

With a small select team, master-cutter Gabi Tolkowsky took almost three years to complete the crystal´s transformation into the world's largest, most modern-cut, top-colour, flawless diamond.

Boasting 247 facets - 164 on the stone and 83 on its girdle - 'Centenary' is only surpassed in size by the 530.20 carat 'Great Star of Africa' and the 317.40 carat 'Lesser Star of Africa', both of which are set into the British Crown Jewels. The 'Centenary' diamond was unveiled, appropriately at the Tower of London in May,1991.


The Regent

The exceptional limpidity and perfect cut of the Regent,found in India in 1698, gives it an incontestable reputation as the most beautiful diamond in the world. At 140.50 carats, it was acquired by Thomas Pitt, Governor of Madras, who sent it to England to be cut.



Quite a fickle little thing, the Regent,in 1717,made its way to France, where it snuggled into the band of Louis XV's silver gilt crown (in the Louvre) at his coronation in 1722, then moved to Louis XVI's crown in 1775.

Later in 1801 it featured on the hilt of the First Consul's sword (Fontainebleau, Musée Napoléon 1st), and then flashed around on the Emperor's two-edged sword in 1812.

In 1825 it dazzled on the coronation crown of Charles X, and during the Second Empire, it embellished the "Grecian diadem" of the Empress Eugenie. Now it languishes in Louvre in Paris with some other famous bits and bobs.


Koh-i-Noor (Mountain of Light)

Now part of the British Crown Jewels, the105.60 carats, oval-cut gem,Mountain of Lightdates back to1304, and has the longest history of all the famous diamonds.

It was captured by the Rajahs of Malwa in the sixteenth century by the Mogul Sultan Babur and remained in the possession of later Mogul emperors. Some believe it was set in the famous Peacock Throne made for Shah Jehan, but that after the break-up of the Persian empire, the diamond found its way to India, possibly via Afghanistan with one of Nadir Shah´s bodyguards, who fled with the stone when the Shah was murdered and tried in vain, to buy military help from Ranjit Singh of the Punjab.



After fighting broke out between the Sikhs and the British, the East India Company claimed the diamond as a partial indemnity and presented it to Queen Victoria in 1850. On leaving India, the stone weighed l986 carats, but was cut to l08.93 carats and worn in a brooch until Queen Alexandra and Queen Mary had it set in the State Crown, which, in 1937, was worn by Queen Elizabeth for her coronation. It is kept in the Tower of London with the other Crown Jewels.


The Idol's Eye

Another famous diamond that was once set in the eye of an idol before it was stolen, the aptly named Idol´s Eye is70.20 carats, a flattened pear-shaped stone the size of a bantam's egg. Legend has it that it was given as ransom for Princess Rasheetah by the Sheik of Kashmir to the Sultan of Turkey who had abducted her.


The Taylor-Burton

The 69.42 carat Taylor-Burton is nearly colourless and nearly imperfection free. The rough 240.80 carat stone was found in the Premier Mine, Transvaal, South Africain 1966 and cut into a 69.42 pear shape diamond.

The name may come as a surprise...or it may not!



Richard Burton bought and named this stone as a gift for Elizabeth Taylor on their engagement. For a cool $1,100,000.

After Burton's death in 1979, Liz Taylor sold the stone for charity and reportedly received $2.8 million, which she donated in his memory to a hospital in Biafra. The stone was last seen in Saudi Arabia.


The Sancy

Charles the Bold, Duke of Burgundy first owned the 55 carats, pear-shaped stone until things went, well, pear-shaped and he lost it in battle in 1477.

The stone is in fact named after a later owner, Seigneur de Sancy, a French Ambassador to Turkey in the late 16th century, who generally loaned it to French kings. First, Henry III wore it in the cap he used to conceal his baldness, then Henry IV of France borrowed the stone. In 1664 James I of England bought it, but, in 1688, James II, last of the Stuart kings of England, fled with it to Paris, back to whence to it came until it disappeared during the French Revolution.



The Blue Hope

Another stone that milled around during the French Revolution, the 45.52 carat Blue Hopeis thought to be a part of the famous Blue Tavernier Diamond, brought to Europe from India in l642.The Blue was purchased initially by King Louis XIV who had it cut to 67.50 carats from 112 carats to bring out its brilliance.

The diamond was stolen during the French Revolution, and a smaller diamond of similar colour was sold in 1830 to Henry Thomas Hope, an English banker, hence the name.

Ironically, the Blue Hope´s owners have a long history of bad luck. After inheriting the diamond, Hope's son lost his fortune. The family of another owner,Mrs. Edward McLean, an American widow, suffered a series of catastrophes: her only child was accidentally killed, the family broke up, Mrs. McLean lost her money, and then committed suicide. When Harry Winston, the New York diamond merchant, bought the stone in 1949, many clients refused to touch the stone. It is now on display at the Smithsonian Institute in Washington.




Named after the Queen of Holland, the step-daughter of Napoleon Bonaparte, this 20-carat, peach-coloured gem is part of the French Crown Jewels and may be viewed at the Louvre in Paris.


He liked his jewellery did Richard Burton. His first jewellery purchase for Elizabeth Taylor was the 33.19-carat Asscher-cut Krupp Diamond, in 1968. Originally, the stone belonged to thesecond wife of the steel magnate Alfred Krupp, Vera Krupp.

Taylor had the stone set in a ring and wore it just about everywhere and for everything.


Diamond Trivia

Diamonds were formed between 3.3 billion and 900 million years ago, yet man did not discover them until after 2500 BC.

The word diamond came from the ancient Greek word ´adamas´ meaning unconquerable.

Diamond is the hardest substance known to man – 140 times harder than ruby or sapphire and 180 times harder than emerald.

Over 250 tonnes of ore must be mined in order to produce a one-carat polished stone.

Every diamond is unique -- no two stones are the same.

The 4C´s, Cut, Colour, Carat weight and Clarity combine to produce a value for each stone.

The largest diamond ever found, the Cullinan, weighed 3106 carats. The two largest stones cut from the Cullinan are set in The Crown Jewels.

The slogan ´a diamond is forever´ was penned over 50 years ago and recently won the award for the best advertising campaign ever.

The first diamond engagement ring was made in 1477 when the Archduke Maximilian of Austria gave it to Mary of Burgundy.