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Diamond
 
Basics | Why are they so expensive? | What to look for | Colour | Clarity | Cut | Carat | Fakes
 
Basics
The name Diamond is a corruption of the Latin word 'Adamis' or 'Adamant' meaning The Invincible.
Diamond is pure carbon, just the same as graphite (a pencil lead), or coal. The difference is that it was formed about 30 to 40 million years ago under great heat in the Earth's magma, and forced up under enormous pressure into the Earth's crust. Most Diamonds are found in South Africa, and The Ural Mountains in Russia. Lesser deposits are found in India, North America, and Brazil.
Diamond is the hardest natural substance known to man, so it can only be cut or scratched with another Diamond. Because of its hardness, when polished it achieves a high lustre. It also has a very high refractive index which disperses the light that passes through it, giving the stone the 'Fire' or sparkle that makes it so beautiful.
Diamond Crystals
 
Why are they
so expensive ?
Diamond is not a rare mineral, but what comes out of the ground is mostly black or gray material called 'Bort' and is used for industrial abrasives and cutters. It takes about 50 tons of solid rock to yield one carat of Diamond, about 20% of which is gem quality, of this only about 5% is of the best quality. Larger single gem quality crystals are much rarer.
The rough crystal is hewn into its basic shape by spinning it in a lathe and rubbing it with a Diamond tipped tool. Usually about 30% of the original crystal is lost. From there it is cut by a Diamond impregnated saw, and polished with powdered Diamond paste. This process is time consuming and wasteful, as it can take about 8 hours to cut once through a one carat stone, and it can take days to polish the facets on. Although there is much automation, larger stones are cut and polished by hand, and measured by eye.
After polishing, the finished Diamonds are sorted and graded by colour, clarity, and weight. From there they are bought and sold by dealers mainly in Antwerp and London.
Diamond sorting
What to look for
Buying Diamond jewellery can be a stressful time for the customer, as he or she is faced with spending a large amount of money on a tiny object, which can still be something of a mystery to some. This requires putting trust in the retailer to help him or her buy the right Diamond at the right price. As a general rule of thumb, jewellers tend to stock jewellery set with Diamonds of a good commercial quality. The best quality Diamonds are rare, and very expensive, while the lesser quality ones can lack fire and sparkle. So retailers tend to choose stock Diamonds of good colour and clarity, while being affordable to most customers. If the customer has a certain budget, he or she can make an informed decision whether to choose a larger Diamond of lesser quality, or a smaller Diamond of higher quality, or something in between.
There are four basic qualities that affect the price of Diamonds, they are Colour, Clarity, Cut, and Carat weight. Known as the 4C's. When comparing prices between retailers, ask for these properties and compare like for like, as the price of a Diamond can vary enormously between a similar sized Diamond of a different quality.
It is a good thing to have some background knowledge of a product before you buy, but please remember that Diamonds unlike Cars or Computers, are a natural product, and do vary, so the retailer may not always have a certain Diamond of a certain weight, clarity or colour in stock all the time.
May's Ring
 
Colour
The colour of a Diamond is a natural quality and is more or less not effected by man, although some Diamonds can be irradiated to enhance the colour especially in fancy coloured stones.
The older terms 'Blue White' 'Commercial white' 'Wesselton' and 'River' have been replaced by the modern Gemological Institute of America (GIA) standard of colour which starts at D and finishes at Z.
True to nature, the most desirable colourless or white (D colour) is the most rare. The more colour they have, the more available they become. Therefore you pay a premium for the whiter (colourless) Stone.
The difference in colour between a D-E coloured stone and an H-I coloured stone is hardly noticeable to the un-trained eye, so in the trade we usually buy around the G-H-I range for a good 'Commercial' colour.
 
Diamond Colour D-E Diamond Colour F-G Diamond Colour H-I Diamond Colour J-K Diamond Colour L-M Diamond Colour N-O Diamond Colour P-Q Diamond Colour R-S Diamond Colour T-U Diamond Colour V-Z
D-E F-G H-I J-K L-M N-O P-Q R-S T-U V-Z
Clarity

Most natural gemstones contain some type of inclusions. Inclusions are tiny imperfections within the stone. In Diamond the most common inclusions are specks of carbon that have not crystallized and appear as black dots. Other inclusions can be crystals of other material, and show as tiny coloured specks. Some inclusions can be cracks, fissures, and bubbles, which are harder to find as they are usually white or colourless. The clarity of a Diamond is mostly a natural property, although modern technology allows some inclusions to be removed by lazer.
The GIA standards for clarity have replaced the older terms 'Piqué 1-3' with 'I 1-3'. The grading system is shown below:
IF or FL (Internally Flawless or Flawless).
VVS (Very Very Small inclusions, or Very Very Slightly imperfect) grades 1 and 2.
VS (Very Small inclusions, or Very Slightly imperfect) grades 1 and 2.
SI (Small Inclusions, or Slightly Imperfect) grades 1 and 2, and finally,
I (Included, or Imperfect) grades 1 to 3.
The presence of inclusions in a gemstone affect the passage of light through it, so the more inclusions a stone has, the less light gets through, and therefore less sparkle. Also in nature, flawless crystals are rarer than ones with inclusions, and therefore more desirable, and more expensive.
A perfectly flawless stone will not look too different to a slightly included stone to the average person, so a Diamond of VVS or VS would be a good quality purchase at a better price.

 
Diamond Clarity IF-FL Diamond Clarity VVS1 Diamond Clarity VVS2 Diamond Clarity VS1 Diamond Clarity VS2 Diamond Clarity SI1 Diamond Clarity SI2 Diamond Clarity I1 Diamond Clarity I2 Diamond Clarity I3
IF-FL VVS1 VVS2 VS1 VS2 SI1 SI2 I1 I2 I3
Cut
This is the only property of a Diamond that is totally influenced by man. Cut is not only a shape that is desired, it can also influence the optical properties of the stone. There is a very precise geometrical ideal that allows the light entering the stone reflect and refract internally, and be dispersed through the crown facets (above the girdle). Too deep or shallow in the pavilion (below the girdle) and the light leaks out everywhere. Inclusions can be hidden under facets if the cutter and polisher work out where to start cutting the rough crystal.
The quality of cut has some bearing on the price of the stone, but not as much as the colour and the clarity. Some fancy cuts like hearts, trilliants and pear shapes are more wasteful than others, so therefore cost more per carat than a plain round brilliant or princess cut.
 
Diamond Cut Round Diamond Cut Princess Diamond Cut Marquise Diamond Cut Baguette Diamond Cut Trilliant
Round Brilliant Princess Marquise Baguette Trilliant
Diamond Cut Oval Diamond Cut Emerald Diamond Cut Heart Diamond Cut Pear
Oval Emerald Heart Pear
Carat
Carat weight is a metric measurement of weight, and is equal to 200mg. This can be confused with the carat quality of Gold, which is the ratio of Gold to base metal in the alloy. For example 18 carat Gold is 18 parts per 24 of Gold which divides out to 0.75 or 750 parts per 1000 Gold.
All gem stones are measured in metric carats, there are 100 points to a carat, so a stone weighing 0.25 of a carat can be expressed as 25 points.
It is also useful to remember that all gems have different specific gravities, with Diamond being quite high, therefore a one carat round brilliant cut Diamond will be smaller than a similarly cut Sapphire of the same weight.
The most important factor to look out for is the fact that we pay a premium for stones above certain sizes. Diamonds of under 0.25ct. are a similar price per carat for similar quality, when you get over the 0.25ct weight, the price jumps up. when you get to the magic 0.50ct mark, the price per carat for similar qualities leaps even higher. When you get to the even more magic one carat mark, the price starts to rise enormously, due to the fact that larger single crystals are harder to find, and a 'One Carat Diamond' is most peoples perceived ideal.
 
 
Fakes
As with all things that are expensive there will always be imitations, such as Rolex watches, or Nike trainers. Diamonds are just the same, and now it is very acceptable to wear jewellery which contains imitation Diamonds. The problem arises when the gemstone you are buying is sold to you as a natural Diamond, at a natural Diamond price. That is fraud. Cases of customers being defrauded by high street jewellers are very rare indeed. It simply is not worth while doing, because sooner or later they will be found out, and will never work again in the trade.
Moissanite is totally man made, it is very hard, but not quite as hard as Diamond, but much harder than Sapphire, so it will pass the scratch test. Most Jewellers use a small thermal probe to quickly check for Diamond, unfortunately Moissanite will pass this test too, although there are now new testers that will check against it. Optically it looks too good to be true, because it has a much higher rate of dispersion, in other words it has too much 'fire'. Moissanite stones do not contain the natural inclusions that Diamonds have, but can contain manufacturing flaws which appear as white hair like rods running vertically within the stone. The best check for Moissanite is to look for double refraction within the stone. Diamond is one of the few gemstones that is singularly refractive, Moissanite is not. This can only be seen with a 10x lens, and will reveal 'doubling' of the back facets when viewed though the table facet.
Cubic Zirconium (CZ) is totally man made, and has been used for many years as a Diamond simulant, and these days it is regarded more or less as costume jewellery. CZ is singularly refractive like Diamond, but there are two or three checks for CZ. One is to look for scuffs and rubs on the facets, because CZ is relatively soft, it is susceptible to knocks and scratches. CZ also lacks the dispersion of Diamond and can look a little dead and plastic looking, especially when it has been worn as jewellery for a little while. Also if you put a loose CZ stone face down on a piece of white paper, it will look 'glassy' i.e. you can see straight through it, unlike Diamond which will still display some sparkle.
Diamond Synthetic
Me
If you have any questions about buying Diamonds, please contact me by clicking on the e-mail button at the top of this page on your left. Unfortunately I cannot supply any Diamonds from this site, but I am very happy to give advice.