The traditional diamond growth method was developed in the 1950s. It involves the use of expensive equipment creating very high-pressures and high-temperatures (referred to as HPHT). This process takes about 5 days to grow a 1-carat crystal that, due to the unique laboratory growth conditions, forms a very distinctive shape. The most common colors for these synthetic diamonds are yellow and brownish yellow, though others such as blue, pink, red and green are also possible.

But over the past decade, a new method for growing diamonds has emerged: chemical vapor deposition, or CVD. Instead of using high-pressure machines, diamond crystals grow from a gas at very low pressures in a vacuum chamber. Only a few companies have the skill to use this process, and most diamond crystals are less than .5 carats and form a tabular  shape, which differs from that of natural diamonds. In contrast to the older HPHT method, this method can grow colorless crystals, while making colors such as blue, yellow, pink, red and green possible as well.

[Note: in both processes, blue is due to the presence of boron in the diamond, while the other colors are the result of a post-growth treatment process involving radiation exposure and sometimes heating]

As synthetic diamond production continues to rise, it’s becoming an even greater necessity to know exactly what you’re buying. To properly identify the differences between a synthetic diamond and a natural one, be sure to receive a professional lab evaluation.

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Contrary to what many people may think, the word “synthetic” does not mean fake when it comes to gemstones. The term actually comes from the Greek word for “to put together.” People “build” or, more accurately, “grow” synthetic crystals. They do this by using chemicals that, given the proper environment, arrange themselves into crystals of essentially the same structure as crystals that grow without human intervention.

A synthetic gem is a man-made material with essentially the same chemical composition, crystal structure and optical and physical properties as the natural gem material.

The two most basic facts about synthetic gems are:

The composition and structure of a laboratory-grown synthetic ruby, for example, are essentially the same as those of a natural ruby. The synthetic ruby weighs the same as a natural ruby of equal size. There are, however, slightly different characteristics between the two, including tell-tale inclusions and growth patterns. Gemologists rely on these differences to identify synthetic from natural.

Learning about the most common types of synthetics will help you better understand why they vary in price and in quality. It’s important to remember that most people can’t distinguish between synthetics and stones mined from the earth. So when considering the purchase of any costly gemstone, it’s smart to request a reputable third-party diamond report, like GIA’s, to be sure about what you’re paying for.

Stay tuned for a four-part series on how synthetic stones are created, their relative value and how they should be sold in the marketplace.

Photo provided by GIA and Tino Hammid

The post What are Synthetic Gemstones? appeared first on GIA 4Cs Blog.

Early attempts to synthesize diamonds date all the way back to the nineteenth century. But the process of duplicating the extreme heat and pressure under which natural diamonds are formed was elusive. In 1955, General Electric overcame these technological barriers and produced small, industrial-quality stones – the first synthetic diamonds. Since then, the processes of synthesizing diamonds have gotten better and better.

Gem-quality synthetic diamonds have been available to consumers since the mid-1980s. While they represent a small segment of the market, they are becoming more widespread and increasingly difficult to detect when purchasing diamonds. GIA is at the forefront in meeting this challenge, giving a distinct report for synthetics so that there is no confusion in the marketplace.

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