August 2, 2023
Synthetic Gemstones

Synthetic Gemstones

To the untrained eye, it can be difficult to distinguish a clear, impeccably cut gemstone from a synthetic gemstone. After all, both types of gemstones have the same physical properties and chemical composition, making it difficult to distinguish between the two types.

However, closer inspection through the eyes of an expert can often reveal some telltale signs that the gem is a synthetic gemstone and not a natural gem. Fortunately, a gemmological report or certificate can determine beyond doubt whether a gemstone is of natural or artificial origin.

In the following article we would like to clarify the differences, inform and describe the manufacturing process and history of synthetically produced gemstones.

What are synthetic gemstones

A synthetic gemstone is artificially grown or produced in a laboratory. An artificially produced gemstone has virtually all the chemical, optical and physical properties of its natural gemstone. Imitation, on the other hand, is made of a different material, has a different chemical composition and / or different physical properties than the natural stone to be imitated.

Examples of synthetic beryl including the synthetic emerald variety
Examples of synthetic beryl including the synthetic emerald variety
(source: GIA)

How synthetic gemstones are made

Synthetic gemstone crystals have been produced since the late 19th century, and their production is often characterized by the need in industrial applications outside the jewelry industry. The first success was the production of synthetic ruby of cuttable quality. Over the years, more and more gemstone types have been produced synthetically, increasingly for the jewelry industry to meet the growing market and low prices for the masses.

Depending on the type of gemstone, a wide variety of processes are used to artificially produce the gemstone in the laboratory. There is no one answer to how gemstones are artificially or synthetically produced. But more about that later, when we take a closer look at the processes for individual gemstone types.

The advantages and disadvantages of synthetic gemstones

There are both advantages and disadvantages to purchasing synthetic gemstones. The main reason why many people want to buy synthetic gemstones is, of course, the lower price.

However, at first glance, man-made gemstones also offer other advantages. For example, it is more environmentally friendly to produce synthetic stones than to engage in overexploitation of natural, ancient pieces. However, the CO2 emissions to produce artificial gemstones are enormous and responsible mining for man and nature creates a livelihood for the miners.

The main disadvantages include lower value and alter properties. For example, a man-made diamond will never be as hard as the real thing. Thus, related uses such as cutting with a diamond are also eliminated.

In addition, artificial stones always lose value, while real gemstones become more and more valuable. This is because the production of synthetic gemstones is becoming more and more precise and better, while the number of real gemstones is limited. So, if you want to use gemstones as an investment, you should buy genuine gemstones.


• Cheaper than real gemstones

• Often hardly distinguishable from the real thing

You read the arguments "more environmentally friendly" and "more sustainable" everywhere, but synthetically produced gemstones are not. If you do responsible mining of natural gemstones this is more resource-friendly and sustainable for people and nature.


• Always lose value

• Other properties of the stone

• Not suitable for investment

How to Identify Synthetic Gemstones

Recognizing "real" gemstones, respectively the correct classification of a stone is often challenging even for experts. While the trained eye of the specialist can distinguish gemstones from crude fakes or imitations, determining a piece in terms of treatments or origin can be complicated without laboratory analysis.

In any case, to be sure that you are buying a natural gemstone, you should only buy stones with a certificate from an independent gemological institute or laboratory. A gemstone certificate not only proves the mineral group but also always states whether it is a natural gemstone or a synthesis, and also addresses the question of treatments or origin.

Differences between natural and synthetic gemstones

Here are five important differences between the two types:

1) Synthetic gemstones are manufactured in laboratories, while natural gemstones are mined.

Synthetic gemstones, also known as "man-made gemstones" or "cultured gemstones," owe their name to the fact that they are scientifically manufactured or "cultured" in a laboratory. During the manufacturing process, pressure and temperature are usually applied to carbon and other elements. Natural gemstones, on the other hand, are found far below the earth's surface and must be mined.

2) Natural gemstones usually have more inclusions than synthetic gemstones.

Synthetic gemstones are often described as "too perfect." This is because no impurities have penetrated the stone and they have far fewer inclusions than natural gemstones. An inclusion is an imperfection in the gemstone that can affect its color or luster.

3) Synthetic gemstones are usually more brilliant in color than natural gemstones.

Synthetic gemstones have far fewer inclusions and therefore often have a more brilliant color than natural gemstones. However, it is important to distinguish between natural gemstones that have been treated and synthetic gemstones that simply have a more "perfect" appearance due to the lack of inclusions.

4) Natural gemstones are much rarer and more valuable than most synthetic gemstones.

Natural gemstones have their charm and specialness in rarity and rarity compared to industrially produced synthetic gemstones from the laboratory. A natural sapphire is much more expensive than a lab-produced sapphire because of its rarity. To be honest, you can't compare the two. The differences in value are extreme. Synthetic gemstones have a value of zero in the narrow sense of experts and a natural gemstone has its permanent intrinsic value and corresponding value development.

5) Synthetic gemstones cost much less than natural gemstones of comparable size and color.

In general, synthetic gemstones cost about 30% to 40% less than natural gemstones of the same type, size, and cut. For this reason, synthetic gemstones are sometimes chosen for engagement rings and other gifts by cost-conscious buyers looking for a beautiful looking stone for themselves or a loved one.

In addition to these five differences, there are many other characteristics that make natural gemstones rare and unique. For example, many natural gemstones are sold with a certificate of authenticity that verifies the clarity, cut, and weight of the stone. Buying a gemstone with a certificate is an effective way to increase the value of a natural gemstone.

However, it is important to know that natural gemstones are a good investment opportunity because they always increase in value over time, while synthetic stones only look nice but actually have a value of zero today as well as in the future.

Synthetic ruby can be produced by flux growth
Synthetic ruby can be produced by flux growth
(source: GIA)

Types of Synthetic Gemstones

There are quite a few synthetic gemstones including diamonds, corundum (sapphire and ruby), emeralds, spinel, quartz, opal, alexandrite to name a few that are commonly present in the market.

Synthetic Gemstones

In detail, we would like to go into more detail about the following 6 known types of gemstones and briefly explain their artificial production and history:

1. Synthetic Diamond

These lab-grown diamonds have most of the characteristics of their natural counterparts. They are essentially made of carbon. There are essentially 2 processes:

- Chemical vapor deposition (CVD). Growth of diamonds occurs in a vacuum chamber through a chemical reaction that releases carbon atoms that deposit on diamond seed plates.

- High Pressure High Temperature (HPHT) process. Growth of diamonds from a melt flow in which carbon dissolves at higher temperatures and diamonds form on seed crystals in a lower temperature portion of the growth chamber.

Some synthetic diamonds are produced by chemical vapor deposition (CVD)
Some synthetic diamonds are produced by chemical vapor deposition (CVD)
(Source GIA)

Some diamonds are made in high pressure high temperature environments also in a variety of colors
Some diamonds are made in high pressure high temperature environments also in a variety of colors
(Source: GIA)

2. Synthetic Corundum (Sapphire and Ruby)

Rubies and sapphires can also be produced artificially in the laboratory for almost 150 years. The first synthetic corundum was produced as early as 1877 by the French scientist Edmond Fremy. Shortly thereafter, the chemist Auguste Verneuil developed a process to artificially produce corundum on a larger scale.

In the Verneuil process named after him, synthetic rubies and sapphires can be produced in almost any color, from colorless to yellow, orange, green, blue and red.

In addition to the Verneuil process, synthetic sapphire and ruby are also successfully produced using drawing and fluxing processes. The starting point in all processes is molten aluminum oxide, which then crystallizes out on so-called "seed crystals". In the hydrothermal process, additional work is carried out under overpressure.

However, it is possible to distinguish it from natural corundum because synthetic corundum shows curved growth streaks, streaky color zoning, gas bubbles and inclusions of the fluxes used under the microscope.

Synthetic corundum, which includes ruby and sapphire, can be produced by most processes. For this reason, a synthetic corundum is available in many price ranges, from very cheap to very expensive and also widely available in the market.

Synthetic corundum can be made in a variety of ways
Synthetic corundum can be made in a variety of ways
(Source: GIA)

3. Synthetic Emerald

Synthetic beryls come in many colors, including yellow, red, blue (aquamarine) and green (emerald). In the late 1980s-1990s, Russia became a major producer of these synthetic gemstones and is still a major supplier of hydrothermally grown gemstones such as synthetic beryl and synthetic corundum, as well as other gemstones such as synthetic diamond and synthetic alexandrite.

In the late 1930s, scientists finally succeeded in synthesizing a commercially viable version of this sought-after deep green gemstone using the fluxing process. Hydrothermal synthetic emerald for jewelry came on the market in 1960.

Artificially produced in the laboratory emeralds look confusingly similar to the natural, real emeralds
Artificially produced in the laboratory emeralds look confusingly similar to the natural, real emeralds
(Source: GIA)

4. Synthetic Spinel

In the early twentieth century, researchers accidentally produced synthetic blue spinel while trying to grow a synthetic blue sapphire. Since then, synthetic spinel has been widely used as a substitute for many natural gemstones. In the 1990's, a new flux grown synthetic spinel produced in Russia was introduced in a variety of colors, including red, a color made possible with the older flame fusion process.

The synthetic spinels shown here are in crystal form, and can be produced in any color
The synthetic spinels shown here are in crystal form, and can be produced in any color
(Source: GIA)

5. Synthetic Opal

In the 1970s, the Gilson Company developed a three-step process for producing compelling synthetic opal. First, microscopic spheres of silica are created by precipitation. Then, the spheres are stored in acidic water for more than a year. Finally, the spheres are solidified with a hydrostatic press without distorting the stacking arrangement that creates the opal's color play.

These synthetic opals can look like very valuable natural white and black opals to the untrained eye
These synthetic opals can look like very valuable natural white and black opals to the untrained eye
(Source: GIA)

6. Synthetic Alexandrite

Since there is not enough natural alexandrite to meet the demand, various synthetic materials have entered the market in recent decades. Alexandrite has been synthesized by a number of different processes, including Czochralski, Floating Zone, and Flux. Synthetic corundum with color change is also often used to mimic natural alexandrite. In rare cases, synthetic spinel with color change can also be found on the market.

Synthetic alexandrite such as this stone shown in its incandescent and daylight colors
Synthetic alexandrite such as this stone shown in its incandescent and daylight colors
(Source: GIA)

There are differences in artificially made gemstones

There are many ways how gemstones are artificially made, we would like to describe 4 variations of different artificially made variations in more detail:

1. Composite stones

Compounding and mixing other substances are a relatively simple way to make a gemstone appear artificially more beautiful. For example, less valuable stones or other substances such as glass can be added to increase the weight and improve the clarity. This is called a composite.

A good example of this is also the so-called pressed amber. In this process, which was already used in 1880, several small ambers are pressed together to form a larger amber. Large findings are namely, insofar as they are natural, significantly more valuable than small gems.

The process of pressing small pieces together to form a large one is very popular overall, for example, also with lapis lazuli.

2. Gemstone imitations

The situation is different with imitation gemstones. These resemble the real gemstones when viewed with the naked eye but have different characteristics. An imitation is made of a different material, has a different chemical composition and/or different physical properties than the natural stone being imitated.

Imitations are usually made of colored glass, plastic or resin. An example of this is rhinestone (also known as simili, rhinestone or rhinestone). This is glass that looks diamond-like due to special grinding processes, among other things.

However, real gemstones can also be used for imitations. For example, it is common to dye low-grade spinel so that it looks like a high-grade gemstone.

3. Treated Gemstones

Another method to artificially increase the value of a stone is to treat it. Gemstones can be treated in 3 ways:

- By heating a stone to about 300 to 600 Celsius, the color can become more intense and uniform. Through the so-called firing, however, small defects such as cloudiness or unwanted inclusions can also be concealed, for example. Fired gemstones are not subject to declaration.

- Some, rather porous, gemstones are also dyed directly. In this way, for example, very colorful agates can be produced. Unfortunately, the coloring is not subject to mandatory labeling, so it is very difficult to identify them.

- Another method to change the gemstone color is irradiation by radioactive substances or X-rays. Since the gemstone can become radioactive in this process, it must first be quarantined (sometimes for years). Irradiated gemstones must be marked as "irradiated" or "treated".

4. Dublette & Triplette (Doublet & Triplet)

The so-called doublet and triplet are also among the imitations of gemstones. Here, different layers, partly of genuine gemstone and partly of other materials, are put together to form a new solid. On the one hand this saves material, on the other hand it also protects the gemstone from damage (e.g. also from contact with the body, sweat etc.).

In a duplicate, a very thin layer of genuine gemstone is glued to a base. The base can be e.g. plastic, synthetic or cheaper gemstones.

In the case of the triplet, only the middle layer consists of the genuine gemstone, which is bound at the top by a top layer and at the bottom by a bottom layer. This protects the gemstone from outside influences. Doublets and triplets must be declared as such.

Synthetic sapphires look confusingly similar to natural sapphires
Synthetic sapphires look confusingly similar to natural sapphires
(source: GIA)

How we can help

First, a clear statement. For us, synthetically produced gemstones have no value. No matter how beautiful or large they are. They are an artificial product from the laboratory that can be created as often as you like. This is fine for industrial use, but not for jewelry, no matter what kind of gemstone it is.

The myth and the specialness and not least its value is measured with the gemstone by its rarity, the rarity. This is a lasting value today and tomorrow. The natural beauty of a gemstone may not always be perfect it is however nature and not an artificially produced industrial product.

When mining is done in a way that conserves resources and is fair to all involved, as is the case with our sapphires from Sri Lanka, this is an additional argument for a beautiful, natural gemstone that has been sustainably extracted from nature. You have a lasting value, the beauty of nature and a good conscience where the gemstone comes from and under which conditions it has been mined, namely in harmony with nature and the local people.

Natural sapphires from CEYLONS, untreated and unheated from responsible mining practice
Natural sapphires from CEYLONS, untreated and unheated from responsible mining practice

We are happy to support you with our fine & fair Ceylon Sapphires, directly from our mines in Sri Lanka through a transparent and traceable supply chain. Approach us directly as a goldsmith, or ask your trusted goldsmith to pick out a sapphire for you from us.

Click here to Email us | Browse our Sapphires


What is a synthetic stone?

A gemstone produced artificially in a laboratory that usually has the same properties as a natural gemstone but can be reproduced as desired.

Which gemstones can be produced synthetically?

Very many types of gemstones, such as diamonds, corundum (sapphire, ruby), emeralds and other beryls, spinels, opals, alexandrites and many more.

How to recognize synthetic gemstones?

Through a gemmological laboratory appraisal or certificate, which can examine the natural characteristics of the gemstone and find out indications of artificial manufacturing processes without any doubt.

How much does a synthetic diamond cost?

A synthetic diamond costs about 20-30% less than a natural diamond. This is not much when buying but when selling it plays a huge role. Of course, the exact price depends on its size, color, clarity and cut.

How is a synthetic diamond made?

Synthetic diamonds are produced from graphite in the so-called "HPHT process" under high, hydraulically generated pressure of up to 60,000 bar at a temperature of more than 1500 degrees Celsius.

Can synthetic diamonds be distinguished from real diamonds?

A synthetic diamond is confusingly like a real diamond. The difference cannot be seen with the naked eye, a microscope, or a magnifying glass: The only way to be sure that you have purchased a genuine diamond is to ask for a certificate of authenticity.

How does a fake diamond shine under UV light?

Under UV light, the diamond is completely dark and does not glow blue. The fluorescence is very weak and not visible. There is also no glow under UV light.

What is synthetic sapphire?

Sapphire crystal is high purity synthetic sapphire (single crystal) which is made from molten aluminum oxide. The chemical formula is Al2O3. Sapphire crystal is slightly less sensitive to impact than conventional quartz or mineral crystal and has very high light transmission and refraction.

How is synthetic ruby made?

Synthetic ruby is the red variety of the mineral corundum. It is produced with the help of flame fusion process; the red color is created by traces of chromium.

What is a synthetic opal?

Synthetic opals are grown, for example, in a laboratory. Such imitation opals are made of substitutes and not real opal.

Is a cubic zircon a diamond?

No, a cubic zircon is classified as a diamond simulant - a stone that looks similar to natural diamonds but is made of a different material. Natural and lab-grown diamonds are made of carbon, while cubic zirconia is made of zirconia (ZrO2).

What is synthetic amethyst?

Glass and zirconia are the two materials commonly used to imitate amethysts. In the process of making glass, whose elementary component is quartz sand, the color of glass can be influenced by adding coloring components.

Are zirconia valuable?

No, a zirconia remains a gemstone with low value. Accordingly, the price of this stone in a piece of jewelry is exceedingly low. 1 carat, or 20 g, is in the price range of about 20 - 150 €, depending on the color and intensity. Even though a high quality cubic zirconia looks damn similar to a real diamond, it is an artificially produced stone with the lowest value.


Leander Schorr

Leander Schorr, the Co-Founder of CEYLONS MUNICH, is a respected figure in the gemstone industry. With a focus on ethical practices, he ensures that CEYLONS offers a wide selection of fine and fair sapphires, complete with traceable origins. Leander’s & Dr. Janowski's groundbreaking initiative, ECOMINE, stands as the world's first self-sustaining mine for Fair Sapphires, highlighting the dedication to responsible sourcing.

CEYLONS | MUNICH stands for the finest Ceylon sapphires. A brand committed to responsible mining of Sri Lankan gemstones obtained in an ethical manner.

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