About Diamonds
At DeJoria, we only use the top 20% of available diamonds from around the world. As a result, you can be sure that your DeJoria diamond will provide a magical sparkle for life.
As part of your diamond jewellery buying experience, it is important to understand how a diamond is graded in terms of its characteristics. An estate agent, for example, can't determine the price of a house without knowing its size, condition, location etc. This is also true for a diamond.
Fortunately, there is an internationally recognised system for diamond grading - called the "4Cs": Cut, Carat, Colour and Clarity...
The cut of diamonds most usually refers to the actual physical shape of diamonds, with round brilliant cut diamonds being the most available and popular, comprising around 70% of the total market, with other 'fancy' shaped diamonds also available.
The cut can also refer to the way the diamond is proportioned. The better the cut of diamonds, typically the more brilliance displayed and, therefore, the greater the value. Cut grades are generally classed as one of Fair, Good, Very Good or Excellent. NOTE - Not all diamonds have a cut grade. Call us on 0845 355 1164 for more information.
ROUND BRILLIANT CUT - The most popular of all the diamond shapes, with 58 facets which are cut to maximise the sparkle and fire of the diamond. Click here to view round brilliant cut diamond engagement rings.
Hint...look for
Depth 58-63% & Table 53-60%
Symmetry & Polish - Good+
PRINCESS CUT - Having grown in popularity in recent years, princess cut diamonds are square in shape a dn have 76 facets, so display wonderful sparkle and brilliance. Click here to view princess cut diamond engagement rings.
Hint...look for
Depth 60-75% & Table 60-75%
Symmetry & Polish - Good+
Length to Width Ratio - As close as possible to 1.00:1.00

EMERALD CUT - Rectangular in shape, emerald cut diamonds are 'step-cut' and have rows of facets, usually 48 to 50, that resemble a staircase.Click here to view emerald cut diamond engagement rings.
Hint...look for
Depth 60-69% & Table 60-75%
Symmetry & Polish - Good+
Length to Width Ratio - Close to 1.50:1.00


MARQUISE CUT - These diamonds are long and slender and have 56 facets, so wonderful sparkle. Click here to view marquise cut diamond engagement rings.
Hint...look for
Depth 59-65% & Table 52-64%
Symmetry & Polish - Good+
Length to Width Ratio - Between 1.75:1.00 - 2.10:1.00

OVAL CUT - These provide a similar amount of sparkle to round cut diamonds and have 56 facets. Click here to view oval cut diamond engagement rings.
Hint...look for
Depth 58-65% & Table 54-64%
Symmetry & Polish - Good+
Length to Width Ratio - Between 1.33:1.00 - 1.66:1.00

PEAR CUT - Traditionally a teardrop in shape, pear cut diamonds have a total of 58 facets, prokecting superb sparkle. Click here to view pear cut diamond engagement rings.
Hint...look for
Depth 58-65% & Table 52-64%
Symmetry & Polish - Good+
Length to Width Ratio - Between 1.40:1.00 - 1.75:1.00

HEART CUT - These are essentially pear cut diamonds with a cleft at the top. Click here to view heart cut diamond engagement rings.
Hint...look for
Depth - 58-65%
Table - 55-60%
Symmetry & Polish - Good+
Length to Width Ratio - Close to 1.00:1.00

RADIANT CUT - These diamonds are either rectangular or square in shape with cut corners, with around 70 facets.
Hint...look for
Depth 60-69%
Table 60-69%
Symmetry & Polish - Good+
Length to Width Ratio - Close to 1.00:1.00 for squarish, or 1.10+:1.00 for elongated

ASSCHER CUT - Asscher cut diamonds are typically square in shape with chamfered corners, with the 57 step cut facets of emerald cut diamonds.
Hint...look for
Depth - 60-70%
Table - 60-70%
Symmetry & Polish - Good+
Length to Width Ratio - Between 1.00:1.00 - 1.05:1.00

CUSHION CUT - Cut with a total of 60 facets, cushion cut diamonds are similar to round diamonds or oval cut diamonds.
Hint...look for
Depth - 65-75%
Table - 65-75%
Symmetry & Polish - Good+
Length to Width Ratio - Close to 1.00:1.00, or 1.10+:1.00 for elongated

The word "carat" is taken from the carob seeds that people once used in ancient times to balance scales. This was standardised in 1907 - one carat became 0.2 grams. Furthermore, one carat is divided into 100 "points". Therefore, 25 points is ¼ carat, 50 points is ¼ carat and so on.
Diamonds are rare. The larger the diamond, the rarer it is - larger diamonds, therefore, have a greater value per carat. For that reason, the price of a diamond rises exponentially with its size. This is not always to say, however, that the larger the diamond the more valuable it is compared with a smaller stone. This is dependent upon other characteristics as well.
The following table shows key carat weights relate to size in millimetres for various shaped diamonds.
|
Approximate stone sizes in millimetres |
|||||||
| Carat Weight |
Round Brilliant |
Princess | Emerald | Marquise | Oval | Pear | Heart |
| 0.25ct | 4.2 | 3.3sq | L4 x W3 | L5 x W3 | L5 x W3 | L4.5 x W2.5 | 3.9 |
| 0.30ct | 4.4 | 3.5sq | L4.5 x W3 | L6 x W3 | L5 x W3.25 | L5 x W3 | 4.0 |
| 0.33ct | 4.5 | 3.7sq | L5 x W3 | L6.5 x W3.5 | L5 x W2.75 | L5.25 x W3.25 | 4.5 |
| 0.40ct | 4.8 | 3.9sq | L5 x W4 | L7 x W4 | L5 x W4 | L5.5 x W3.5 | 4.75 |
| 0.45ct | 5.0 | 4.0sq | L5.5 x W4 | L7.5 x W4 | L5.25 x W4.25 | L5.75 x W3.75 | 4.8 |
| 0.50ct | 5.2 | 4.2sq | L6 x W3 | L8 x W4 | L5.5 x W4.5 | L6 x W4 | 4.8 |
| 0.55ct | 5.4 | 4.4sq | L6 x W3.5 | L8 x W4.5 | L5.75 x W4.5 | L6.25 x W4.25 | 4.95 |
| 0.60ct | 5.5 | 4.5sq | L6 x W4 | L8.25 x W5.5 | L6.25 x W4.5 | L6.4 x W4.4 | 5.1 |
| 0.65ct | 5.7 | 4.6sq | L6.25 x W4 | L8.5 x W6.5 | L6.5 x W4.5 | L6.6 x W6.6 | 5.25 |
| 0.70ct | 5.8 | 4.75sq | L6.25 x W4.25 | L9 x W4 | L6.75 x W4.75 | L6.8 x W6.8 | 5.4 |
| 0.75ct | 5.9 | 4.8sq | L6.5 x W4.5 | L9 x W4.5 | L7 x W5 | L7 x W5 | 5.6 |
| 0.80ct | 6.1 | 4.85sq | L6.75 x W4.5 | L9 x W5 | L7.1 x W5.1 | L7.2 x W5 | 5.8 |
| 0.85ct | 6.2 | 4.9sq | L6.75 x W4.75 | L9.25 x W5 | L7.2 x W5.2 | L7.4 x W5 | 5.9 |
| 0.90ct | 6.3 | 5.0sq | L6.85 x W4.85 | L9.5 x W5 | L7.3 x W5.3 | L7.6 x W5 | 5.95 |
| 0.95ct | 6.4 | 5.1sq | L7 x W4.85 | L9.75 x W5 | L7.4 x W5.4 | L7.8 x W5 | 6.0 |
| 1.00ct | 6.5 | 5.25sq | L7 x W5 | L10 x W5 | L7.5 x W5.5 | L8 x W5 | 6.0 |
| 1.25ct | 7.0 | 5.9sq | L7.5 x W5.5 | L10.5 x W5 | L8 x W6 | L8.5 x W5.5 | 6.5 |
| 1.50ct | 7.5 | 6.0sq | L8 x W6 | L11 x W5 | L8.5 x W6.5 | L9 x W6 | 6.9 |
| 1.75ct | 7.9 | 6.25sq | L8.25 x W6.25 | L11 x W5.5 | L9 x W6 | L9.5 x W6.5 | 7.3 |
| 2.00ct | 8.2 | 6.5sq | L8.5 x W6.5 | L12 x W6 | L9 x W7 | L10 x W7 | 7.5 |
| 2.25ct | 8.5 | 7.0sq | L8.75 x W6.75 | L12.5 x W6 | L9.25 x W7.25 | L11 x W7 | 7.9 |
| 2.50ct | 8.9 | 7.5sq | L9 x W7 | L13 x W5.5 | L9.5 x W7.5 | L12 x W7 | 8.4 |
| 2.75ct | 9.0 | 8.0sq | L9.5 x W7.5 | L13 x W6 | L9.75 x W7.75 | L12.25 x W7.5 | 8.6 |
| 3.00ct | 9.4 | 8.25sq | L10 x W8 | L14 x W7 | L10 x W8 | L12.5 x W7.75 | 8.9 |
| 3.25ct | 9.6 | 8.5sq | L10.25 x W8.25 | L14.5 x W7 | L10 x W8.25 | L12.75 x W8 | 9.1 |
| 3.50ct | 9.9 | 8.75sq | L10.5 x W8.5 | L15 x W7 | L10 x W8.5 | L13 x W8.25 | 9.4 |
| 3.75ct | 10.1 | 9.0sq | L10.75 x W8.75 | L15.5 x W8 | L10.5 x W8.75 | L13.25 x W8.75 | 9.6 |
| 4.00ct | 10.4 | 9.25sq | L11 x W9 | L15.5 x W8.5 | L11 x W9 | L13.25 x W9 | 9.9 |
You can download this PDF document and print it out to see diamond sizes to scale, at the various carat weights - DOWNLOAD DIAMOND SIZES PDF [Opens in a new window]
The most valuable diamonds are colourless. They allow most light to pass through the stone and create the most brilliance. However, very few diamonds are colourless, so most diamonds will have some yellow in them - the less yellow the better. The colour scale goes from D to Z (no diamond of colour A, B or C has ever been found), with D being the most white and Z being the most yellow. At DeJoria, our minimum quality threshold is colour J (slightly tinted yellow). For comparison purposes, the majority of diamonds in a high street jewellers shop are 'Commercial grade' quality which, if graded on this scale, would be approx colour K / L.

So, a typical GIA certificated diamond would manifest itself as follows:
D - Exceptionally white
E - Exceptionally white
F - Rare White
G - White
H - White
I - Slightly tinted white
J - Slightly tinted white
Any diamonds with a colour grade of less than J are rejected.
The clearer the diamond, the greater its brilliance, and the greater its value. Most diamonds have blemishes, called 'inclusions' which are nature's birthmark of the stone. These can be tiny traces of carbon (black spots), air pockets (white spots) or other naturally occurring phenomena. Diamond clarity ranges from diamonds without any flaws (internally flawless) to those that have visible inclusions. At DeJoria, our minimum quality threshold is SI2 ("Slightly Included" - not visible with the naked eye). For comparison purposes, the majority of diamonds in a high street jewellers are 'Commercial grade' quality which, if graded on this scale, would be approx clarity I1 / I2.

So, a typical GIA certificated diamond would manifest itself as follows:
IF - Flawless, or Internally Flawless
VVS1 - Very, Very Slightly Included. Requires 60x magnification to see any inclusions
VVS2 - Very, Very Slightly Included. Requires 60x magnification to see any inclusions
VS1 - Very Slightly Included. Requires 30x magnification to see any inclusions
VS2 - Very Slightly Included. Requires 30x magnification to see any inclusions
SI1 - Slightly Included. Generally requires 10x magnification to see any inclusions
SI2 - Slightly Included. Generally requires 10x magnification to see any inclusions
Any diamonds with a clarity grade of less than SI2 are rejected.
More educational material and information follows...
Polish relates to the smoothness of the diamond's facets. Symmetry on the other hand relates to the facet alignment. A diamond possessing a poor polish means that the surface of a facet can be dulled and may result in reduced sparkle. With poor symmetry, the internal refraction of light can be "misdirected", again resulting in a reduced emission of sparkle.
The outer edge of a diamond.

Whilst being a fairly minor consideration in relation to other characteristics of a diamond, specific reference to a diamond?s girdle is made on most diamond grading certificates.
Ideal girdle thickness should range anywhere between Very Thin to Thick. However, as an example, a diamond with a perfect medium girdle around 90% of its diameter and a very thick girdle at one isolated point would receive a GIA girdle grade as "Medium to Very Thick", which would probably be perfectly acceptable as the fact that a tiny part of the girdle is Very Thick compared to the rest of the girdle is unlikely to detrimentally affect the overall appearance of the diamond. In general, diamonds that have girdle grades of Extremely Thin, Very Thick or Extremely Thick are usually not recommended.
Common abbreviations for diamond girdle used are -
EXTN, ET, XT, EXN - Extremely Thin
VTN, VT, VETN - Very Thin
T, TN, TH - Thin
M, ME, MD, MED - Medium
STK, ST, SLTK, SLTH - Slightly Thick
T, TK, TH - Thick
VTK, VTH, VETK, VET - Very Thick
ET, EXTK, XT, XTK - Extremely Thick
Because of their perfect internal symmetry, Hearts and Arrows cut diamonds exhibit a unique pattern of eight pointed arrows and eight perfect hearts. More importantly, however, these diamonds maximise light return and have more brilliance, fire and scintillation than any other diamond cuts. It takes an experienced diamond cutter many years before he is able to achieve such a level of perfection. Due to the fact that most diamond cutters are paid by the piece, many prefer to produce higher volumes of less well cut diamonds catering for the 'masses' rather than produce fewer Hearts and Arrows cut diamonds which not only take around 2-3 times longer to finish, but also result in around 15% more wastage of diamond in the cutting process. Over the course of a single year, therefore, it is easy to comprehend the amount of man hours and the amount of wastage associated with these diamonds and, therefore, helps to explain why only a few specialist diamond cutters in the world work in this field. Because these diamonds are scarce in supply yet highly sought after, you can expect to pay a price premium of around 5-10% compared to other well cut diamonds. Please note that not all Hearts and Arrows cut diamonds will have reference to this on their diamond certificate. The GIA, for example, do not make reference to "H&A" whereas other laboratories such as HRD and EGL USA, for example, do make reference on their grading reports.
Whilst the acquisition of a diamond engagement ring or other piece of diamond jewellery is an important expression of love or accomplishment, it also represents a major investment in time, energy and money. You need and deserve to feel confident in the integrity of what you've acquired. There is no typical industry standard for diamond certification in the UK - and therefore, you'll find that the majority of diamond jewellery in a high street jewellers will be non-certified. At DeJoria, we believe it is vital that you buy certified diamonds for your peace of mind. At DeJoria, we use GIA, IGI, AGS, HRD and EGL certified diamonds. Click here for more information.
Today, an illegal trade exists within the diamond industry whereby the profits generated by the mining of diamonds - predominantly in 3rd world countries - have been used to fund wars and terrorist activity. These are known as "conflict diamonds" or "blood diamonds". The Kimberley Process was established in 2000 between governments across the world in an attempt to eradicate this disgraceful activity, and DeJoria wholeheartedly supports this initiative for we believe that wherever you purchase your diamond engagement rings, diamond eternity rings, diamond rings and diamond jewellery, the diamonds should ALWAYS be conflict-free, and not tarnished by a dark history. For more information, click here.

Wherever possible, DeJoria uses recycled precious metals.
Diamond jewellery in the UK is traditionally produced using either white gold (9kt and 18kt), yellow gold (9kt and 18kt) or 950 platinum. We also now offer palladium, which has recently been introduced into the market, as well as 18kt rose gold.
For solitaire diamond engagement rings and diamond eternity rings, platinum has experienced an enormous boom in popularity in recent years. White and yellow gold are much more prominent in other items such as diamond earrings, diamond pendants, diamond bracelets, diamond necklaces and other modern diamond rings.
CARATS OR KARATS?
Don't confuse the two terms. Carat (often abbreviated to "ct") is specifically used to describe diamond weight, whilst Karat (often abbreviated to "kt") is specifically used for precious metal grading. Karats are simply the percentage of gold in a piece of jewellery. The established categories for gold karats and their gold percentages are;
24kt = 100% gold
22kt = 91.7% gold
18kt = 75% gold
14kt = 58.35% gold
12kt = 50% gold
10kt = 41.7% gold
In the UK, we mainly use 9kt and 18kt gold as it is important for gold, when being used for diamond jewellery, to be combined with other alloys to strengthen it - see further information on this below.
PLATINUM

At 95% pure, platinum is the purest of all the precious metals - this is why it is sometimes referred to as 950 platinum. This purity provides a stunning metallic finish to diamond engagement rings, for example, as it is perfect for maximising the brilliance of the diamond itself. Platinum is rare, and is 30 times rarer than gold. In fact, it is estimated that if all the platinum in the world were poured into a single Olympic sized swimming pool, it would scarcely be deep enough to cover your ankles!
So, why is platinum so popular? The key to this lies in platinum's density and weight, which makes it much more durable than other jewellery metals. As a result, firstly, it provides the most secure setting for the diamond in diamond engagement rings. Like all precious metals, platinum scratches. However, the scratch on an item of platinum diamond jewellery is merely a displacement of the metal and none of its volume is lost. Finally, platinum's purity makes it hypoallergenic and ideal for those with sensitive skin.
WHITE GOLD / YELLOW GOLD / ROSE GOLD
At DeJoria Diamonds, we only use the 18kt versions of these metals. Gold itself is a metallic element. In its pure form, it is too soft to be used for making diamond jewellery. As a result, white gold is actually 75% gold mixed with other alloys to provide it with the required strength. Whilst white and yellow gold do provide secure settings for diamonds in diamond engagement rings and other items of diamond jewellery, they are not as secure as platinum.
When a piece of white gold diamond jewellery has been produced, it is plated in rhodium which provides the item with its shiny finish. Over time, however, especially for items which are worn on a daily basis such as diamond engagement rings or diamond eternity rings, for example, the rhodium can tarnish and so white gold diamond jewellery may need re-polishing every 18 months or so.
Rose gold, which is also known as pink gold or red gold, derives it reddish colour from being 25% copper and 75% gold. Rose gold provides a warm, individual and unique finish to diamond jewellery.
PALLADIUM
Palladium is a noble metal and a member of the platinum group. It is rarer than gold. Although platinum continues to be the preferred white metal for most - due to its pureness and durability - white gold has traditionally been the only lower price alternative. Palladium is durable and has a bright, white natural colour that doesn't tarnish and so does not need a plating like white gold. Therefore, palladium provides many of the properties of platinum but at a lower price point.
KEY FACTS ABOUT PRECIOUS METALS

HALLMARKING
Gold, silver and platinum are used as an alloy in the manufacture of precious metal jewellery. The precious metal is mixed with other elements to give it the properties, such as flexibility and durability, needed to produce a desirable article. Even the most experienced jeweller or chemist cannot tell, just by looking at the item of diamond jewellery, how much precious metal there is in the alloy or whether a thick plating of precious metal is making a base metal core. This offers the unscrupulous a huge opportunity for fraud and there is a need to protect the public from those who may try to cheat them.
Therefore, it is a legal requirement in the UK (but not so the case in other countries) for all items of precious metal jewellery to be "hallmarked", to conform with the legal standards of the Hallmarking Act, 1973.
In the UK, hallmarking a long history, dating back nearly 700 years, and representing the earliest form of consumer protection. The consumer benefits in many ways.
Hallmarks are small markings stamped on gold, silver and platinum items. A hallmark means that the article has been independently tested and guarantees that it conforms to all legal standards of purity (fineness). These tests are carried out only by an Assay Office, of which there are four in the UK - London, Birmingham, Sheffield and Edinburgh.
The Hallmarking Act 1973 changed on January 1 1999 and allows articles of higher and lower standards of fineness to be sold. This brings UK law into line with European law. Consumers may now choose from a much wider range of goods but continue to benefit from the same level of protection.
It is illegal for any trader to sell or describe a precious metal article as gold, silver or platinum unless it is hallmarked. Gold articles weighing less than 1 gram, silver articles weighing less than 7.78 grams and platinum articles weighing less than half a gram and exempt from hallmarking.
THE HALLMARKING PROCESS
Before any article can be hallmarked, it has to be assayed - ie tested - to check how much precious metal the item contains. To do this, minute laboratory-sized samples are scraped from the items and are then weighed accurately.
A "fire refining" process, which selectively removes all the other elements in the sample, is used to assay gold.
In the case of silver, a process called "potentiometric titration" is used to determine the silver content of the sample in parts per thousand.
Platinum, which was brought under hallmarking regulations in 1973, is assayed by a process called "inductively coupled plasma-optical emission spectrophotometry".
The results of these test determine the standard of purity mark applied to the items.
HISTORY OF HALLMARKING
In 1238, Henry III commanded the Mayor of London to appoint six faithful and discreet goldsmiths who would be responsible for ensuring standards for gold and silver articles. Later, Edward I passed a statute requiring not only that all silver articles were to be of sterling standard, the same as coinage, but also they they were to be assayed by the Wardens of the Goldsmiths' Guild and marked with a leopard's head.
In 1327, the Goldsmiths' Guild recieved its first Royal Charter from Edwards III which confirmed its responsibility for assaying and marking. The Worshipful Company of Goldsmiths, as the guild was later called, is still responsible for the London Assay Office.
Under another statute in 1363, makers were ordered to stamp their own distinguishing marks alongside the leopard's head. Originally, the maker's mark took the form of a device, such as a cross or a fish; later, it became the practice to use the initials of the worker or firm.
In December 1478, the company appointed a salaried Assayer and compelled makers to bring their completed silverwares to Goldsmiths' Hall to be assayed and marked before they were offered for sale. This practice has continued to the present day and is the origin of the word 'hallmark'. In the same year, an additional mark - the date letter - was introduced by the company. This consisted of a letter of the alphabet which was changed anually. When one alphabet cycle was completed, the style of the letter or its surrounding shield was altered.
Hallmarking continued during succeeding centuries at Goldsmiths' Hall and at the Assay Offices, which later opened in other towns, such as Newcastle, Exeter and York, where there were working goldsmiths and silversmiths. In Scotland, there were goldsmiths working at a date as early as in England. The earliest records pertain to the goldsmiths of Edinburgh. An Act of Parliament was passed in 1773 establishing Assay Offices in Birmingham and Sheffield.
Several of the provincial offices have now closed - Newcastle, Exeter and York in the 19th century, Chester in 1962 and Glasgow in 1964. The Dublin Assay Office, whose origins date from the early 17th century, continues to operate in Ireland.
For more information on hallmarking in the UK, please visit www.theassayoffice.co.uk
You can rest assured, of course, that all DeJoria diamond jewellery is hallmarked as such - one of the many quality assurances you receive from us.
INDEPENDENT INSURANCE VALUATIONS
DeJoria also provides an independent insurance valuation dossier on all 'Create Your Diamond Ring' items and higher valued items in our 'Diamond Gift Boutique', where the item is appraised and examined by an independent gemologist. This dossier serves 2 important purposes - Firstly, it provides our clients with complete piece of mind that the diamond jewellery they have purchased is indeed the genuine article. Secondly, loss or damage of a personal item is always distressing, but think how much worse it would be if you have no idea of the worth of the item you have lost and have no way of convincing your insurer of its value. SafeGuard take digital photographs of the diamond jewellery, note any distinguishing features, take a full and accurate description and place a value upon the item for insurance purposes. All this information is permanently stored onto a national computer database providing our clients, the police and your insurer with conclusive proof of ownership.
Single purchases in excess of £10,000 will be accompanied by a 'Jewellery Portfolio' as part of our package. This provides a comprehensive description and valuation of the diamond jewellery, high quality images of the item, and helpful information to explain diamond grading, hallmarking and jewellery care. All this is provided in a luxury leather presentation wallet.
HALLMARKING
It is consumer law in the UK that all precious metal jewellery carry a hallmark. This is a tiny stamp on the inside of the ring mount which is your assurance that the platinum or gold in your precious metal jewellery is indeed that. Hallmarking in this country is carried out by one of the UK Assay Offices - London, Birmingham, Sheffield or Edinburgh. We only use the best quality 950 platinum, or 18kt white / yellow gold for our jewellery.
BRITISH JEWELLERS' ASSOCIATION
The British Jewellers Association is the national trade association which promotes and protects the growth and prosperity of UK jewellery companies. We adhere and support the BJA's Code of Ethics, which are outlined on the our credentials page.
If you would like to personally discuss your specific requirements with one of our in-house diamond experts, please call us on 0845 355 1164 or email info@dejoria.co.uk.









