A brief history of Man Made Gemstones

Imitations of gemstones

Attempts to imitate natural gemstones have been made since before the time of Christ.  The Egyptians were the first to mimic the valuable stones with glass and glazing.  In 1758 a Viennese, Joseph Strasser, developed a type of glass which could be cut and which looked similar to a diamond.  Although the production and sales of these imitations called Strass, were prohibited, they did eventually find their way into the European trade.

Czechoslovakia was an important center for the glass-jewellery industry in the 19th century.  For costume jewellery, cheap glass was used.  For gem imitations, lead or flint glass with a high refractive index was used.  These imitations had a similar colour to that of the original, but certain physical properties such as hardness and lustre could not be satisfactorily imitated.  Therefore, it became the dream of scientists such as Verneuil to fabricate imitation gemstones that really replicated genuine stones in every physical characteristic.  It was only towards the end of the 18th century, that French scientist, Verneuil successfully synthesized rubies at a commercial price.

Green terbium glass

The Verneuil process is known as the Flame Fusion Process.  It is today, still the most common process used for gemstone synthesis due to low production costs and high crystal growth rates. Large numbers of flame fusion gemstones like rubies, sapphires and spinels are readily available. The powdered ingredients are fused together under a high temperature oxy-hydrogen flame. As the powder melts it crystallizes in successive layers. The curved growth layers are important identification features and can be observed under a 10x loupe or microscopic. Sometimes clouds of gas bubbles are visible.

Synthetically produced crystals are NOT classed as imitations by the gem trade, but rather as a separate group, in addition to natural gems.  In the trade, they are referred to as “synthetic”.

Synthetic gemstones

The first man-made gemstones appeared in the early 19th century.  It was only in 1910, when Verneuli successfully produced rubies (red corundum), sapphire (blue corundum) and diamondite that these synthetics became economically viable.  By 1926 synthetic spinels with excellent colour of other gemstones such as aquamarine, tourmaline and blue zircon were produced and are still used today.

Synthetic Aquamarine

The first synthetic emerald was produced in the 1930’s in the USA.  Synthetic emeralds are produced using either flux fusion or hydrothermal methods (high temperature, high pressure water system).  The flux fusion technique is rarely used in fashion jewellery or industrial applications due to very high production costs. This technique also poses the greatest threat to the gemstone trade as flux grown rubies have inclusion patterns that very closely mimic the patterns seen in natural counterparts.  By dissolving ingredients into molten fluids and crystallizing them under controlled conditions, the desired gemstone mineral is produced.

There is no synthetic gemstone on the market today that has had a greater impact n the jewellery trade than Cubic Zirconia.  Cubic Zirconia (CZ) came onto the market around 1978.  The first CZ was made in Russia as an optical stimulant used in their lazer industry.  CZ is made using microwave technology which generate the intense heat required to melt and re-crystalise Zirconium Oxide that has stablilized with Calcium or Yttrium in a process called skull melting.

A word on Cubic Zirconia

Cubic Zirconia is a diamond simulant, not a synthetic diamond. The latter, are diamonds that have been produced in a laboratory rather than naturally occurring, by such companies as General Electric and Mitsubishi.

Cubic Zirconia

A simulant, simply put, is a natural or in the case of Cubic Zirconia a synthetic material that can imitate a natural gemstone.  A successful simulant needs to exhibit similar properties to the material it is intended to simulate. In the case of a diamond simulant it needs to be hard (diamond has a hardness of 10 on the Mohs scale), display excellent brilliance, lustre and fire, and have a colour (or lack of colour) similar to the diamond it is impersonating.

For more information on synthetic and natural gemstones, and gemstone sales in South Africa, please go to our website and online store.  www.touchstonegems.co.za