Gemstones that are created or grown in a laboratory rather than being "found" in the ground after being formed over millions of years are now much more common. Such man-made gems are physically and chemically identical to the naturally occuring gems, and cost much less to produce, and are much more affordable to buy.
The quality of man made or synthetic gems depends on the production method and the quality of the process used. A low quality process is capable of producing synthetic gems in large quantities for a few dollars (or less) a carat. High quality processes are capable of producing excellent quality gems that rival the best of the natural stones, but at a cost. Even so, the high quality man mad gems (paticularly emeralds, spahires and rubies) still cost much less per carat than an equivalent quality natural stone.
There are two primary manufacturing methods used to create synthetic or man made gems: melt growth and solution growth.
Melt-Growth
Two common melt-growth methods are flame fusion (or Verneuil flame fusion) and Czochralski pulled-growth. Both these methods produce relatively low quality gems. The processes use very high temperatures making it difficult to create stones with uniform color (especially in rubies and blue sapphires). Also, action of melting and reforming crystals results in variations in the gems that scatter light and make the stone look dull.
(a) Verneuil Flame Fusion
Flame fusion was the first technology used for growing gems in a laboratory. This technique is still widely used to produce rubies and sapphires. The method is low cost, but the gems are also low quality. Gems produced with this method are often used in cheap jewelry found in discount stores and in class rings. A competent jeweler should be able to identify a synthetic gem made with this process from the thin narrow grooves that are typically formed as the molten material cools and hardens.
(b) Pulled-Growth
The Czochralski pulled-growth method is also commonly used to create rubies and sapphires, but it is a more complicated and expensive process, although it does produce better quality gems than flame fusion.
Solution-Growth
Some believe that solution growth leads to higher quality gems than melt-growth. There are two common solution growth techniques: flux and hydrothermal.
(a) Flux Method
In addition to creating the “big three” (emerald, ruby, and sapphire), the flux method is used to grow spinel and alexandrite. This method uses a supersaturated chemical bath to form the crystals. Flux Method or Flux Fusion — not to be confused with Flame Fusion — creates the highest quality and most expensive synthetic corundum (rubies and sapphires).
(b) Hydrothermal Method
High quality emerald, as well as the less common aquamarine, morganite, and beryl, can be lab grown by the hydrothermal method. It uses a water solution at very high temperature and pressure and takes several months to create a batch of gems. That’s one of the reasons higher quality created gems cost so much more.
Should you consider buying a synthetic gemstone? This is a difficult question to answer. To some people, nothing can replace the urge of owning a beautiful and unique product of nature. To others, what they see is most important and — thanks to high-quality created gems that everyone can own a “museum quality” gemstone at an affordable price.
