×
MESSAGE US

Enquire

Email Phone

We'll always treat your personal details with the utmost care and will never sell your information to anyone else. Read our full Privacy Policy and Terms & Conditions to find out how we use your data.

I have read and accept the Privacy Policy and Terms of Service.

Please ring us for further information:

00353 (0)53 94 30866

September 06, 2019 5 min read

ethical diamond

How to tell the Difference Between Natural Diamonds and Lab Grown Diamonds.

Knowing the Difference, this blog is information taken directly from the Gemelogical Institue of America G.I.A. 

Natural diamonds have long fascinated mankind with their unique physical and visual properties. Features such as exceptional hardness, durability, light reflectivity (brilliance) and dispersion (fire) distinguish them from other gems. The beauty and universal appeal of natural diamonds come at a price, as the recovery and fashioning of such rare gems are challenging. For decades, researchers have sought alternatives by creating less expensive “look-alikes” in the form of simulants and, more recently, “duplicates” with Laboratory Grown Diamonds. 

Though such attempts by man to recreate the properties and structure of natural diamonds are nothing new, a rapid increase in Laboratory Grown Diamond growth technology over the past decade has led to real concerns regarding their identification.

Fortunately, GIA has followed the developments of Laboratory Grown diamonds for more than 60 years. This continuum—combined with fundamental research on tens of millions of natural diamonds—allows GIA to accurately identify synthetic diamonds.

In order to protect yourself and your clients against misrepresentations and misconceptions surrounding natural diamonds, Laboratory grown Diamonds and diamond simulants, it is important that you understand the differences among them and the means of their identification.

Unlike diamond simulants, which can be recognised by using standard gem testing, Laboratory Diamonds have essentially the same chemical composition and crystal structure as natural diamonds, but are made in laboratories—not grown in the earth. Because their optical and physical properties are nearly identical to natural diamonds’, identifying Lab-Grown Diamonds is complex. However, because of their artificial growth environments, Lab-Diamonds exhibit several diagnostic features that allow for their detection in gemological laboratories.

Natural Diamonds

Natural diamonds are a wonder of science, as they occur only when atoms of carbon are exposed to high pressures and temperatures about 100 miles (160 kilometers) below the earth’s surface in what geologists call the upper mantle. Diamond crystals reside in these extreme mantle conditions for millions of years. The crystals that grow under these conditions have a unique structure we associate with natural diamonds.

Natural diamond crystals sometimes incorporate solid small inclusions of diamonds or other minerals into their structure as they grow. While mineral inclusions are often considered a negative clarity feature in a polished diamond, they are of tremendous value to geoscientists. Natural diamonds provide a way for these mineral inclusions to be preserved and brought to the earth’s surface where they can be scientifically studied. Because certain inclusions contain radioactive elements that decay at a known rate, the minerals can also be used to calculate the age of diamond formation.

diamond education
diamond education

 

Following their extended time in residence in the mantle, some diamonds are brought to the earth’s surface by volcanic eruptions of kimberlite magma. Geologists believe that the diamonds are transported by the magma very quickly over the 100-mile distance (in just a week or more), so that the diamonds are not physically changed in the process and transformed to graphite. During this rapid upward journey, the diamond crystal can, however, break along cleavage directions, and undergo other changes that may affect, for example, its colour.

diamond education

diamond education

Laboratory-Grown Diamonds

Although their use for jewellry purposes is a somewhat recent occurrence, Laboratory-Grown Diamonds have been produced for industrial applications since the 1950s. Unlike natural diamonds, Lab-Grown Diamonds are grown in laboratories, over a very short period of time – likely just two or three weeks (or less). A longer growth period results in larger crystals; however, steady environmental conditions must be maintained to ensure the formation of high-quality crystals. Currently, the production of Lab-Grown Diamonds in melee sizes is what is most encountered. The drastically shorter growth period of Lab-Grown Diamonds results in features that are of diagnostic value in separating them from natural diamonds.

 

The two growth methods are used to create synthetic diamonds: HPHT and CVD. HPHT (high pressure/high temperature) synthesis, developed in
the 1950s, uses high temperatures and pressures, a molten metal flux and a diamond seed to initiate crystal formation. The result is a distinctive crystal shape which is a combination of octahedral and cube faces and a flat base. The HPHT process more closely mirrors the conditions of natural diamond formation than CVD.

 

The CVD (chemical vapor deposition) method, which was mostly developed during the past decade, produces diamonds through the use of low pressures and high temperatures in a vacuum chamber. A carbon-containing gas such as methane is introduced into the chamber, and gas molecules break down there into the constituent atoms. The carbon atoms “rain” down onto flat diamond seed plates, resulting in a square-shaped, tabular synthetic diamond crystal.

diamond education

Lab Created diamonds

diamond education

Lab Created diamonds growing

Laboratory-Grown Diamond Identification

Because of the contrasting conditions of natural and artificial formation, Laboratory Grown diamonds display several features which allow them to be gemologically distinguished from natural diamonds. These include visual characteristics such as colour zoning, dark metallic inclusions, weak strain patterns and distinctive patterns and colours of ultraviolet fluorescence. Because they represent types of diamonds that are rare in nature, Laboratory grown diamonds also possess additional features that can be detected with gemological instruments.

Decades of research, in addition to the use and development of advanced scientific instrumentation, enable GIA to accurately identify Lab grown diamonds. GIA’s Diamond CheckTM and recent introduction of a fully automated Melee Analysis Service allow for fast and accurate separation of loose natural diamonds from Lab Diamonds.

Information on Laboratory Diamond identification has been published extensively in GIA’s peer- reviewed Gems & Gemology over the last 30 years.

Environmental Information

Every manufacturing industry, including natural and Laboratory-grown diamond, has a carbon footprint.

Natural production :  the Argyle mine uses 7.5kWh ti recover a 1 carat diamond

Laboratory-Grown Production : Gemesis diamond used 20kWh for a normal growth run.

There are also socio-economic considerations that are important in evaluating the mining and manufacturing of Diamonds..

The Future of Man Made Diamonds

No one knows for sure if man-made diamonds will become a popular choice for shoppers long-term. There are personal choice issues for each buyer to consider before they purchase one.

“It is up to the preference of the consumer whether they purchase a natural or synthetic diamond, however, proper disclosure about the nature of their stone is paramount,” says Wuyi Wang, director of GIA’s research and development. “As long as the origin of the diamonds is fully disclosed, consumers and the market will determine the future for synthetic diamonds.”

No one knows for sure if man-made diamonds will become a popular choice for shoppers long-term. There are personal choice issues for each buyer to consider before they purchase one.

“It is up to the preference of the consumer whether they purchase a natural or synthetic diamond, however, proper disclosure about the nature of their stone is paramount,” says Wuyi Wang, director of GIA’s research and development. “As long as the origin of the diamonds is fully disclosed, consumers and the market will determine the future for synthetic diamonds.”

Growing Lab Created Diamonds

Youtube video courtesy of Tech Insider



Leave a comment

Comments will be approved before showing up.