Welcome to theDiamond Certification Laboratoryof Australia

The DCLA Difference

The Diamond Certification Laboratory of Australia (DCLA) is one of the world’s foremost independent diamond grading and certification laboratories, providing independent and guaranteed diamond grading certificates, or diamond grading reports, for natural diamonds. 

DCLA is Australia's premier diamond grading laboratory, and the only laboratory grading diamonds to the IDC rules. The IDC rules are the internationally recognised and accepted rules for diamond grading and diamond certification as set out by the WFDB, IDMA and Cibjo.

The DCLA Diamond Grading Laboratory Certificate sets the standard for technical ability in certification of diamonds. The DCLA remains the only internationally recognised diamond certification laboratory in Australia, grading diamonds in accordance with International Diamond Council (IDC) and World Jewellery Confederation (CIBJO) rules for grading polished diamonds.

Protecting Diamond Buyers

In a relentless pursuit of consumer protection, DCLA is the only diamond grading and certification laboratory, both in Australia and worldwide, to provide a 100% consumer guarantee that a diamond certified by the DCLA laboratory is an accurately graded natural diamond.

The Diamond Certification laboratory of Australia is equipped with the most advanced diamond technology and equipment in Australia. All diamonds submitted to the DCLA laboratory are individually identified and tested to International Diamond Council standards, ensuring that the diamond has not been treated or enhanced in any way, and are of natural origin. 

The DCLA Diamond Grading Certificate assures the owner that the diamond is free of all known diamond treatments and diamond enhancements. The DCLA Certificate confirms that the diamond is a natural diamond and not a man-made synthetic diamond. DCLA state of the art cold laser inscription system permanently links the diamond to the DCLA Diamond Grading Certificate, providing added confidence without altering or damaging the diamond in any way.

Independent & Accurate Diamond Assessment

DCLA Independence means that the DCLA Diamond Grading and Certification Laboratory is autonomous from all diamond and diamond jewellery businesses. The DCLA Laboratory receives no grants or funding from the diamond or jewellery trade, it is completely self funded and independent.

DCLA & The International Diamond Council

The International Diamond Council (IDC) is the governing diamond body established by the World Federation of Diamond Bourses (WFDB) and the International Diamond Manufacturers Association (IDMA). Together, these two organisations are the world’s highest authorities in diamonds.

DCLA is the only International Diamond Council (IDC) laboratory and the only CIBJO Diamond Grading laboratory for Australia, and holds the only official registered National Diamond Masterset for Australia, the diamond C2Au set.

In 1975, the WFDB and the IDMA, appointed a Joint Committee to create an international standard for grading diamonds, covering rules for diamond grading, working methods and nomenclature. A comprehensive system of rules and methods was built up, combining a wealth of practical diamond knowledge and experience of professional diamond people with scientific facts and figures.

The Committee later changed its name to the International Diamond Council (IDC). In May 1978 the "International Rules For Grading Polished Diamonds" were unanimously approved at the 19th Congress of the World Federation of Diamond Bourses and International Diamond Manufacturers Association. All the major diamonds laboratories have since adopted the system. DCLA is proud to offer a Diamond Certificate with such pedigree. 

Trusted and Respected

DCLA is the most respected and trusted name in diamonds protecting the diamond buyer in Australia. Beginning with the wholesaler of diamonds, through to the retail diamond jeweller and, most importantly, you the diamond jewellery or investment diamond consumer.

Before you buy diamond engagement rings or loose unset diamonds, consult the laboratory for independently certified diamond advice. 

What is Diamond?

A diamond is a transparent crystal of tetrahedrally bonded carbon atoms which crystallises into the diamond lattice, a variation of the face centred cubic structure. The word 'diamond' is derived from the ancient Greek word 'adámas', and is the allotrope of carbon, where the carbon atoms are arranged in a variation of cubic crystal structures called the diamond lattice. Diamond is specifically renowned as a material with superlative physical qualities, most of which originate from the strong covalent bonding between its atoms. In particular, diamond has the highest hardness and thermal conductivity of any bulk material synthesized so far.

Because of diamonds extremely rigid lattice it can be contaminated by very few types of impurities including boron and nitrogen, these impurities lend colours to the natural diamond. Small amounts of chemical impurities or defects in the latus alignment produce colours like Blue, yellow, green, purple, pink, orange and the rarest red. Diamonds relatively high optical dispersion gives the stone the ability to disperse light, which results in its characteristic lustre and dispersed colour range.

Natural diamonds are formed at depths of 140 km to 190 km in the Earth mantle at very high pressures and high temperatures. Diamond growth occurred over periods from 1 billion to 3.3 billion years ago. Diamonds are brought to the Earth surface through deep volcanic eruptions by a magma, which cools into igneous rocks known as kimberlites and lamproites.

Diamonds have been treasured as gemstones since their use as religious icons in ancient India where diamonds were first recognized over 3,000 years ago possibly longer, and were first mined in significant alluvial deposits along the Godavari, Penner and Krishna rivers.

The most popular use of diamonds which dates back into antiquity is for Jewellery. The ability of diamond to disperse white light into the spectral colours is a primary gemmological characteristic of the diamond. Because diamond can only be scratched by another diamond, it maintains its polish quality extremely well. Unlike other gems diamond is well suited to daily wear, this contributes to its popularity as engagement or wedding stones worn every day. These attributes contribute to its longevity as a gemstone. The diamond has a hardness of 10 on Mohs scale, ten being the hardest.

In the twentieth century, gemmologists developed methods of grading diamonds along with other gemstones based on the characteristics most important to their value as a gem. Defined by the four main characteristics of gem diamonds, known as the four Cs, and used as the basic description for all diamonds are carat, cut, colour, and clarity.

In natural diamond nitrogen is the most common impurity found in the gem and is responsible for the yellow in diamonds. Diamonds contain impurities or structural defects that cause the coloration, while pure or nearly pure diamonds are transparent and colourless. The Diamond Certification laboratory of Australia (DCLA) classifies the white to yellow diamonds which is cape series, and applies a grading scale from D which is colourless to Z which is light yellow. Fancy Diamonds of a positive colour, such as blue, green, yellow and pink are called fancy coloured and are graded against the Munsel grading scale.

Diamonds high thermal conductivity separate Diamonds from Cubic Zirconia, moissanite and other simulants during basic diamond test. Diamonds do cut glass, but this does not positively identify a diamond as many other materials which are above glass on the Mohs scale of hardness and will scratch or cut glass.

Diamond has a cleavage plane a lot like wood and is therefore more fragile in some orientations than others. Diamond cutters use this attribute to cleave or split some stones prior to cutting.

Rough diamonds occur most often as rounded shapes such as euhedral, octahedra or as twinned octahedra known as macles. As diamond's crystal structure has a cubic arrangement of the atoms, they have many facets that belong to a cube, octahedron, rhombicosidodecahedron, tetrakis hexahedron or disdyakis dodecahedron and the crystal may have rounded edges or be elongated.

Diamonds can also form in other natural high pressure events like in meteorite impacts, known as micro diamonds or nano diamonds are found at impact events sites and can be used to indicate ancient meteor impact craters.
Some diamonds found on Earth did not originated here. A type of diamond called carbonado diamond that is found in South America and Africa may have originated from an asteroid impact.

The magma containing diamond must originate at a depth where diamonds can be formed, three times the depth of source magma for most volcanoes. These small surface volcanic craters extend downward in formations known as volcanic pipes. The pipes contain material that was transported toward the surface by volcanic action which ceased before the volcano material was ejected. Pipes may not contain diamonds at all, those that do may not have enough diamonds to make mining economically viable.

Diamonds pipes which have reached the surface may have been eroded by natural forces and distributed diamonds over a large alluvial area. The pipe is the primary source of diamonds followed by secondary sources including areas where diamonds, eroded out of their kimberlite or lamproite matrix, and accumulated because of water, wind or glacial action. This includes deposits along existing and ancient shorelines, where diamonds tend to accumulate according to size and density.

World wide a large diamond trade exists. Unlike precious metals such as gold or platinum, Diamonds do not trade as a basic commodity due to a substantial mark up in the retail sale of diamonds.

The De Beers diamond advertising campaign is widely acknowledged as one of the most successful and innovative campaigns in history. Even in countries where no diamond engagement tradition had existed. The coordinated campaign has lasted decades and continues today; it is perhaps best captured by the slogan ‘a diamond is forever’,
De Beers controls a significant proportion of the trade in diamonds. They are based in Johannesburg, South Africa and London, England.

The WFDB and The International Diamond Manufacturers Association the recognised authorities in diamonds established the World Diamond Council. The goal is to prevent the trading of diamonds by illicite governments at war. The WFDB activities also include hosting the World Diamond Congress and Presidents meeting alternating every two years. As well these tasks they establishment of the International Diamond Council (IDC) which oversees and sets the rules for diamond grading.

Along the supply chain, members of bourses belonging to the World Federation of Diamond Bourses (WFDB) act as a control for wholesale diamond exchanges, trading both polished and rough diamonds. The WFDB is made up of independent diamond bourses based in major cutting centres such as Tel Aviv, Antwerp, Johannesburg and other cities across the USA, Europe and Asia.

This system manages approximately 130 million carats 26,000 kg which are mined annually, with an approximate value of USD $9 billion.

Roughly half of all diamonds originate from central and southern Africa, the balance is made up of diamonds mined in Canada, India, Russia, Brazil, and Australia. They are mined from kimberlite and lamproite volcanic pipes and fissures, as well as alluvial sources.

The distribution of diamonds is concentrated in traditional diamond trading centres. The most important being Antwerp, where eighty percent of all rough diamonds and fifty percent of all cut diamonds sorted and distributed. Therefore Antwerp is the world diamond capital. Most of the wholesale trade in diamonds is concentrated in a few locations. It is estimated as much as ninety percent of polished diamonds are cut in Surat and Gujarat in India. The other main diamond producing and trading centres are Antwerp, London, New York, Tel Aviv Israel, Gaborone Botswana, Johannesburg South Africa and Amsterdam.

Diamonds which have been polished are sold on diamond exchanges called bourses. There are 26 registered WFDB diamond bourses in the world. Diamond Bourses are the tightly controlled diamond trading floors and a important part of the supply chain. Diamond wholesalers and retailers are able to buy diamonds from producers or dealers at the bourses.

The De Beers Company is the world's largest diamond miner and clearly dominates the diamond mining. De Beers has had control since soon after its founding in 1888 by the British imperialist Cecil Rhodes.
De Beers directly or indirectly controls a significant portion of the world's rough diamond mines and the distribution of rough diamonds.

The De Beers Company sells diamonds to Sightholders, these a select group of companies which have a three year contract with the DTC for a regular supply of rough diamonds cut and polished the rough diamonds for sale to the diamond markets. The cutting and polishing of rough diamonds is a skill. The recent expansion of the diamond cutting works in India, employing efficient, low cost labour, has allowed smaller diamonds to be polished in greater quantities than was previously economically feasible. Cutting centres with lower labour cost control most of the smaller sizes, as well as the larger diamonds. Higher priced larger diamonds are also polished in Europe or North America.

Diamond production of primary deposits started in the 1870s with the discovery of the diamond fields in Kimberly South Africa. World production has increased and now an accumulated total of 4.5 billion carats have been mined since that date. Most of the producing mines are located in South Africa, Botswana, Democratic Republic of Congo, Canada, Zimbabwe, Angola, and Russia.

Diamonds are produced synthetically in a high-pressure high-temperature process which approximately simulates the conditions in nature. An completely different growth technique developed for industrial purposes and used to grow Gem quality diamonds is chemical vapour deposition (CVD). The CVD growth occurs under low pressure and is a process of feeding a mixture of gases into a chamber where they are split into chemically active radicals and ignited by microwaves, arc discharge or laser. The CVD process is commonly used for coatings, but is now able to produce single crystals several millimetres in size. Special gemmological techniques have been specially developed to distinguish natural and synthetic diamonds by analysing the growth structure of the Diamond to identify the origin.

Annual production of gem quality synthetic diamond is a few thousand carats. Diamond purchasers are most likely to see a synthetic when looking for a fancy coloured diamond as synthetic diamonds are made into fancy colours due to the high price of natural fancy colours.
More common are diamond enhancements which are treatments performed on natural or synthetic diamonds. These are designed to improve the perceived the gemological characteristics of the diamond, either for purity or colour. The treatments include laser drilling to disguise inclusions or application of fillings to cracks, treatments to improve the white colour grade, and treatments to improved or introduce fancy colour.
Only trained and equipped laboratories can distinguish between natural diamonds and synthetic diamonds. Laboratories can also identify the treated natural diamonds such as HPHT-treated Type II diamonds.

Laboratories like the DCLA also use specially made machines to aid them in the identification process of treated and synthetic diamonds. Two of the screening machines are the DiamondSure and the DiamondView, both produced by the DTC. Other Laboratories use techniques such as spectroscopy, microscopy and luminescence under shortwave ultraviolet light are used to determine the natural origin of the diamond.