Knowledge
17.04.2026 Synthetic Gemstones
Synthetic gemstones are currently a major topic – especially on social media. But what is really behind them? Are synthetic diamonds and similar stones simply a low-cost alternative, or can they actually compete with natural gemstones?
In this article, we explain the key differences, the production methods, and the crucial question: are synthetic gemstones suitable as an investment?
In The Natural Gem Podcast, Dr. Thomas Schröck talks about substitutions, synthetics, and imitations.
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Further informationWhat Are Synthetic Gemstones?
Synthetic gemstones are stones created in a laboratory that are identical to natural gemstones in their composition. They possess the same chemical, physical, and optical properties – but they are not formed in nature, instead being created under controlled conditions.
Important: synthetic gemstones are not counterfeits, but genuine gemstones – simply of different origin.
How Are Synthetic Gemstones Produced?
Synthetic gemstones are manufactured using processes that imitate natural formation:
- Synthetic diamonds are produced under extreme pressure and high temperatures (the HPHT process)
- Ruby and sapphire (corundum) are created through pulling or melting methods
- The crystal then grows in a controlled way in the laboratory
This production process is technically complex and time-consuming, but it allows for reproducible quality.
Fields of Application for Synthetic Gemstones
Synthetic gemstones are particularly indispensable in industry:
- Laser technology
- Watchmaking industry (e.g. jewel bearings, sapphire glass)
- High-tech applications
In the jewellery sector, they are mainly used because of their lower price.
Recognising and Identifying Genuine Gemstones
Recognising “real” gemstones, or rather correctly classifying a stone, is often challenging even for experts. While the trained eye of a specialist can distinguish gemstones from crude counterfeits or imitations, it can become complicated without laboratory analysis to determine treatments or origin.
Ruby and spinel are a classic example of how similar gemstones can be. Up until around 1800, it was not possible to distinguish red spinel mineralogically from ruby. This is why some of the world’s most famous “rubies” are in fact spinels. One of the most prominent examples is the “Black Prince’s Ruby” in the British Imperial Crown, which, despite its name, is not a ruby at all but a red spinel. Today, distinguishing between the two gemstones is straightforward: spinel is singly refractive, while ruby is doubly refractive.
To ensure that you are buying a natural gemstone, you should always purchase stones only with a certificate from an independent gemmological institute or laboratory. In addition to identifying the mineral group, a gemstone certificate always confirms whether the stone is natural or synthetic and also addresses treatments and origin.
Sometimes misleading designations such as “Balas ruby” for a pale red spinel still originate from times when such distinctions were not yet possible.
“Fake” Gemstones: Imitation or Synthetic?
When it comes to artificial gemstones, a distinction must first be made between a synthetic stone and an imitation.
A gemstone synthesis is a crystal produced in the laboratory that is chemically identical to the natural stone. An imitation, on the other hand, consists of a different material and has a different chemical composition and/or different physical properties from the natural stone it imitates.
A synthetic ruby is therefore chemically a genuine corundum, whereas an imitation merely copies the appearance of a stone. Imitations may be made of coloured glass or other inexpensive materials.
Price and Value Development of Gemstones
A key difference between synthetic and natural gemstones lies in their value:
Synthetic gemstones
- significantly less expensive
- can be produced in unlimited quantities
- no long-term increase in value can be expected
Natural gemstones
- limited availability
- strong demand for top-quality stones
- potential for stable or rising prices
For investors and collectors, this distinction is crucial.
Synthetic Emeralds: Artificial Beryl
The first attempts to produce beryl artificially, and thus emerald, date back to 1848. Emerald was first synthesised on a commercial scale in the 1930s by Jaeger and Espig at the IG Farben gemstone factory in Germany using a flux-growth process.
Depending on the method used, the starting materials include beryllium oxide, aluminium oxide, silicon oxide, and lithium chromate (the latter for colouring), as well as in some cases fragments of natural emeralds, all of which are melted together. As the material cools, new emerald crystals form around seed crystals.
Such synthetics can be distinguished from natural emeralds primarily by residues of flux within the stone and by their overall inclusion pattern.
Natural emerald always contains water, whereas synthetics produced by the flux-growth process are completely water-free. Emeralds created by the hydrothermal process do contain water, but with properties that differ from naturally enclosed water.
This makes the distinction between “natural” and “synthetic” emerald very easy to establish in the laboratory.
Synthetic Ruby & Synthetic Sapphire: Corundum from the Laboratory
Rubies and sapphires, too, have been artificially produced in laboratories for almost 150 years.
The first synthetic corundum was created as early as 1877 by the French scientist Edmond Frémy. Shortly afterwards, the chemist Auguste Verneuil developed a process for producing corundum artificially on a larger scale.
With the process named after him, synthetic rubies and sapphires can be produced in almost all colours, from colourless to yellow, orange, green, blue, and red.
In addition to the Verneuil process, synthetic sapphire and ruby are also successfully produced using pulling methods and flux-growth methods. In all cases, the starting point is molten aluminium oxide, which then crystallises on so-called seed crystals. In the hydrothermal process, production also takes place under pressure.
Distinguishing synthetic corundum from natural corundum is nevertheless possible, as synthetic corundum shows curved growth lines, streaky colour zoning, gas bubbles, and inclusions of the fluxes used when viewed under the microscope.
Synthetic Diamonds
Since the mid-1950s, it has also been possible to produce diamonds synthetically, and even the latest generation of synthetic diamonds can be easily distinguished from natural diamonds by experts.
Whereas synthetic diamonds were initially used mainly in industrial contexts, artificial “lab-grown diamonds” are now increasingly marketed aggressively as affordable jewellery stones.
Are Synthetic Gemstones a Good Investment?
When buying, always pay attention to transparent disclosure: is the gemstone natural or synthetic? Only then can you make an informed decision.
In short: no, in most cases they are not.
While synthetic gemstones can make sense for jewellery or technical applications, they lack one decisive factor for investment purposes: rarity.
Natural gemstones, by contrast, can increase in value over the long term, depending on quality, origin, and market conditions. If you wish to purchase gemstones as an investment, always buy natural, untreated gemstones of the highest possible quality, accompanied by certificates from internationally recognised institutes.
The most interesting stones are the “Big Three” coloured gemstones – ruby, sapphire, and emerald – which are not only value-stable but from which considerable long-term appreciation may also be expected.
Conclusion: Synthetic or Natural?
Synthetic gemstones are an exciting innovation and have a well-established place in technology and jewellery.
However, anyone who values lasting worth, rarity, and investment potential should clearly choose natural gemstones.
Dr. Thomas Schröck
The founder and managing partner of THE NATURAL GEM has been active in international gemstone trading for 30 years. As a doctor of economics and a certified gemmologist in Switzerland, Germany and the USA, among other countries, he is one of Europe’s leading experts on naturally-coloured, untreated gemstones and investments in them.
