Lab Grown Diamonds - Synthetic Diamonds
Man-Made diamonds, which are also referred to as Lab Created diamonds or Synthetic diamonds, are created using highly advanced technological processes within strictly controlled laboratory conditions that mimics the environment under which natural diamonds form in the mantle beneath the Earth’s crust.
In recent years awareness of ethical concerns regarding the humanitarian and ecological issues surrounding the mining of diamonds coupled with the high cost of mined natural diamonds, has led to an increase in the popularity of Man-Made Diamonds.
If you are considering the purchase of a piece of jewellery incorporating a Synthetic diamond then you may be interested to read our guide to this fascinating alternative to natural diamonds:
WHAT EXACTLY IS A MAN-MADE CREATED DIAMOND AND IS IT A REAL DIAMOND?
A Man-Made diamond is essentially a diamond. These Lab Created gemstones are unique in that they are actually pure carbon diamonds displaying identical optical, physical and chemical characteristics as natural diamonds. The only difference is that these diamonds are not cultivated by Mother Nature, but by ‘man’. If you purchase your Man-Made diamond from a legitimate source then there is really no difference between a naturally occurring diamond occurring and a Man-Made diamond cultivated in a laboratory apart from the ‘origin’. Many people incorrectly assume that Man-Made diamonds are not real diamonds and that they are ‘fake diamonds’ but in fact in terms of structure they are just the same as natural mined diamonds.
WHEN WERE MAN-MADE DIAMONDS DEVELOPED?
The very first evidence of scientists creating Synthetic diamonds goes as far back as the late 1800s to 1920s, however, these first creations were analysed but not confirmed. It was in the 1940s that American, Swedish and Russian scientists began to formally grow Lab Created diamonds using the processes of HPHT and CVD. Around 1953 the first reported tiny crystals of Synthetic diamonds were documented. Production of larger Man–Made diamonds for jewellery making and industrial purposes began in the mid-1990s.
HOW ARE MAN-MADE DIAMONDS CREATED?
There are two methods that have been developed to create Man-Made diamonds within laboratory conditions. These are HPHT which stands for high-pressure high-temperature and CVD which refers to chemical vapor deposition. In both processes a diamond crystal or plate is used as a seed to initiate growth of the Man-Made diamond.
HOW ARE MAN-MADE DIAMONDS CREATED BY HPHT?
HPHT (high-pressure high-temperature) is the traditional method of making Synthetic diamonds. The Lab Created diamond is grown within a small capsule that is located inside a mechanism (a press) capable of generating extremely high pressures. The Man-made diamond is formed from a molten metal alloy, such as Iron, Nickel or Cobalt. Within the capsule the diamond powder, is subjected to extremely high pressures and temperatures which dissolve the molten metal flux. This then crystallises over a period of several weeks on the seed to form one or more Synthetic diamond crystals. Natural diamonds grow as octahedral but these Man-Made diamond crystals commonly display cubic faces as well as octahedral ones.
HOW ARE MAN-MADE DIAMONDS CREATED BY CVD?
CVD (chemical vapor deposition) is the newer method of creating Synthetic diamonds and is also referred to as LPHT (low-pressure, high-temperature growth. This scientific process creates the Man-Made diamond inside a vacuum chamber that is filled with gas containing a carbon such as methane. A source of energy freaks down the gas molecules and by this process the carbon atoms move downwards to the flat diamond seed plates. As with HPHT, crystallisation of the diamond occurs anywhere between several weeks and months and it is the time left for growth that determines the thickness of the Lab Created diamond. The number of crystals produced is dependent upon the number of seed plates and the size of the chamber and they often have a rough edge of black graphite and display a brown colouration which can be removed by heat treatment prior to faceting of the Synthetic diamond.
HOW DO LAB CREATED DIAMONDS DIFFER FROM NATURAL DIAMONDS?
Whilst both these gemstones are created by the same primary process and have the same fundamental structure, Lab Created diamonds do differ from natural stones. The main difference between Lab Created diamonds and natural mined diamonds that can be observed is in the clarity of the stones. In addition the process of HPHT is said to produce Man-Made diamonds that are far more robust and hard wearing than natural diamonds.
HOW CAN SYNTHETIC DIAMONDS BE IDENTIFIED FROM NATURAL DIAMONDS?
With the increase in production of Synthetic diamonds for use in items of jewellery there has correspondingly been a vast improvement in the colour and clarity of Lab Created diamonds and an increase in carat weight. Gemologists and jewellers admit that with the improvement in the quality of Man-Made diamonds it is becoming more difficult to identify these gemstones as their chemical and physical properties very closely replicate those of natural diamonds.
However, for the past 30 years the laboratory of the Gemological Institute of America (GIA) has extensively analysed and studied Synthetic diamonds to enable them to identify them apart from natural diamonds. In fact, the GIA report that they have only seen a very small number of Man-Made diamonds submitted unknowingly for their official grading reports.
This GIA lists many of the distinctive visual features of the two kinds of Synthetic diamonds:
- HPHT Synthetic CVD Synthetic
- Uneven colour distribution Even colour distribution
- Graining patterns No graining patterns
- Unusual fluorescence colours Unusual fluorescence colours
- Fluorescence colour patterns Fluorescence colour patterns
- Occasional phosphorescence Occasional phosphorescence
- Metallic flux inclusions Occasional dark pinpoint inclusions
- No strain patterns Banded strain patterns
- Possible inscription on girdle Possible inscription on girdle
The visual features of Synthetic diamonds that the GIA have identified are based upon the characteristics displayed by a number of these Man-Made diamonds. However it should be borne in mind that like natural diamonds not all Lab Created diamonds will display all of these features. Therefore identification of a Synthetic diamond should be based upon the diamond evidencing as many of the identified features as possible.
Synthetic diamonds made by the process of CVD have different gemological properties than HPHT Lab Created diamonds grown material.
Man-Made coloured diamonds created using HPHT process very often exhibit uneven colouration. This is due to how impurities e.g. Nitrogen or Boron are incorporated into the Synthetic diamond during formation. Natural diamonds very occasionally show some colour zoning, but this is not in the geometric pattern shown by HPHT Lab Created diamonds. Colour zoning in coloured HPHT Man-Made diamonds relates to the different crystal faces which results in different patterns than those seen in natural diamonds. In contrast, CVD created Synthetic diamonds normally exhibit quite even colouration and banded strain patterns, and they are of high clarity with few, if any, small dark carbon inclusions.
In HPHT Lab Created diamonds one can often see the inclusion of solidified flux metal. This is seen as black and opaque in transmitted light but displays an almost metallic lustre in reflected light. This is caused by the flux metal alloy used to grow the Man- Made diamond containing elements such as nickel, cobalt and iron. In fact Synthetic diamonds with a high proportion of metallic inclusions can be picked up with a magnet. Man-Made diamonds created by the process of CVD form in a different way, therefore they do not have metallic inclusions. Some natural diamonds contain dark inclusions of graphite or another mineral, but these inclusions do not have a metallic lustre.
If a natural diamond is examined between two polarizing filters placed at a 90-degree angle to one another it will soften display a bright crosshatched or mosaic pattern of interference or “strain” colours. This occurs due to the stresses which are placed upon the natural diamond whilst it was forming in the earth’s mantle or during its eruption to the surface. As Man-Made diamonds form in a controlled environment with no fluctuations in pressure or changes in stress levels, they correspondingly exhibit no strain or weak-banded strain pattern.
The major issue that the GIA have identifies is in the identification of very tiny diamonds, or melee which can include both natural and Lab Created synthetic diamonds. To assist the jewellery trade to overcome this issue the GIA has developed an automated instrument that enables the testing of very small diamonds and as part of their ongoing research program on Man-Made they have recently also set up a CVD growth facility where they are able to produce their own Synthetic diamonds for study.
The best way for a consumer to find out whether a diamond is natural or Lab Created is to always request a certificate upon purchase of the gemstone ask for its certificate (you should not buy diamonds that are not accompanied by such a document). Diamond certificates (see below) issued by the GIA or IGI will indicate if the stone is a Synthetic or a natural diamond.
WHAT COLOURS ARE LAB CREATED DIAMONDS AVAILABLE IN?
For those who appreciate fancy coloured gemstones Lab Created diamonds made by the HPHT process are generally yellow, orangey yellow, or brownish yellow. Almost all are type IIb, which is rare in natural diamonds. By adding boron into the growth process blue Lab Created diamonds are formed. Pink and Red Man-Made diamonds but are less common can be produced by subjecting the crystal post growth to heat treatment processes that involve heating and radiation and heating. Colourless HPHT Synthetic diamonds are very challenging to create as nitrogen needs to be excluded from the growth process therefore modifications to the conditions of growth and equipment is required.
CVD Synthetic diamonds are usually greyish or brownish in colours. The addition of a small amount of boron or nitrogen into the chamber will create diamonds that are yellow, pink-orange, or blue. Colourless crystals are easier to produce with this method, but they require a longer time to grow. Many of the CVD Lab Created colourless diamonds available are believed to have originally been brown crystals decolourised by HPHT annealing. CVD Synthetic diamonds are most commonly type IIa.
Fancy coloured Lab Created diamonds sell at comparatively reasonable prices compared to their natural fancy coloured diamond counterparts.
ARE MAN-MADE DIAMONDS THE SAME AS SIMULATED DIAMONDS?
There is undoubtedly some confusion between Man-Made diamonds and Simulated diamonds, but the simple answer to this question is NO they are NOT the same.
Simulated diamonds do not have the same physical properties as natural diamonds whilst in comparison Man-Made diamonds have the same material properties and elements as natural diamonds, they just originate from the laboratory as opposed to from the earth.
Lab Created diamonds are Man-Made diamonds that consist of actual carbon atoms arranged in the characteristic diamond crystal structure in the same way that natural diamonds are formed. Diamond simulants, such as cubic zirconia and moissanite, are diamond look-alikes. They resemble the appearance and properties of natural diamonds but have a different chemical structure from real diamonds so are not true carbon crystals, they merely imitate the appearance of a diamond.
A diamond simulant may be artificial, natural, or in some cases a combination of these. While their material properties are vastly different from those of natural or Man-Made diamonds, simulants have certain desired characteristics which ideally lend themselves to imitation. Trained Gemologists are able to distinguish natural and Synthetic diamonds from diamond simulants, primarily by visual inspection.
ARE THE PROPERTIES OF MAN-MADE DIAMONDS SIMILAR TO THOSE OF NATURAL DIAMONDS?
The properties of Man-Made diamonds are very much dependent upon the manufacturing process. Some Lab Created diamonds have properties such as hardness, thermal conductivity and electron mobility that are far enhanced to those of many naturally formed diamonds. For this reason Synthetic diamonds are widely used in industrial processes such as in heat sinks, cutting and polishing tools and abrasives. Electronic applications of Man-Made diamonds are in development and Synthetic diamond detectors of ultraviolet (UV) light or high-energy particles are used at high-energy research facilities. Because of its unique combination of thermal and chemical stability, low thermal expansion and high optical transparency in a wide spectral range, Synthetic diamonds are fast becoming the most popular material for optical windows in high-power CO2 lasers and gyrotrons. It is estimated that 98% of industrial grade diamonds are now Man-Made diamonds.
ARE MAN-MADE DIAMONDS EXPENSIVE?
Due to the high cost of the technology and the high consumption of energy required to create Man-Made diamonds, these gemstones do come with a high price tag. A Synthetic diamond is approximately 30%-50% cheaper than a natural mined diamond of equivalent clarity, cut, colour, and size. Whilst Lab Created diamonds are becoming popular with those who have concerns regarding the ethical credentials of some aspects of diamond mining or are on a budget, for many this price differential is not a great enough incentive to choose them over natural diamonds. This is particularly true for those who are purchasing an item of diamond jewellery as an investment.
ARE THEIR ANY ADVATNAGES TO CHOOSING MAN-MADE DIAMONDS?
If price is a factor in your choice of gemstone then one of the major biggest advantages to buying a Man-Made diamond is that it will be a less expensive option. In addition Man-Made diamonds do not usually exhibit large and visible inclusions. Therefore if the factor that you can purchase a flawless, or nearly flawless, diamond at a lower price than that which you would pay for a flawless natural diamond appeals, then a Lab Created diamond is for you.
CAN I WEAR A MAN-MADE DIAMOND AS MY ENGAGEMENT RING?
If you are ethically driven and are looking to combine quality, style and price with your desire to protect the environment, then the option of an engagement ring created using Man-Made diamonds as a centrepiece is a great choice. Plus you will not be sacrificing the look of what is possibly the most important piece of jewellery that you will ever wear.
WHERE CAN I BUY THE VERY BEST QUALITY MAN-MADE DIAMONDS?
If you have now decided that you would like to buy the very best quality Man-Made diamond then you would be well advised to buy your Lab Created diamond from a legitimate and respected diamond retailer that will provide you with certification that your choice of Man-Made diamond has been grown in the laboratory are exhibits exactly the same composition as natural mined diamonds.
Picture: Labgrown manmade diamond for sale in London UK © Reve Diamonds
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