Is Your Ruby Genuine Or Not?

Important: If it seems too good to be true, it almost likely isn't a natural ruby. Clear (Eye-clean) heated and unheated rubies weighing more than 3 carats can be sold for a minimum of $1,000 per carat.

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4 min

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Gem-related Field

Beginner Method
Observe The Color
A natural ruby typically has a deep, vivid red color. Look for a rich, vibrant red, often described as "pigeon's blood" red in the gem trade. The color should be evenly distributed, without any uneven "color spots".

Natural rubies are primarily red, but their hue can vary slightly with hints of other colors like pink, purple, or orange. The most prized rubies are those with a pure, vibrant red without these secondary hues.

Be cautious of rubies that have an unnaturally bright or fluorescent appearance, as this can be a sign of artificial coloring or a synthetic stone. High-quality natural rubies exhibit a strong, rich red saturation, without any brown or gray overtones. The more vivid and pure the red, the more valuable the ruby tends to be. Lower quality rubies might appear dull, with a more washed-out or brownish-red color - but that won't mean they are fake!

In a high-quality ruby, the color should be consistent and balanced throughout the stone. Uneven coloring, such as color zoning (areas of different colors) or patchiness, can reduce the stone's value.

Last but not least, check the ruby's response to light. Observe the ruby under different lighting conditions. Natural rubies should maintain their beauty and color under various light sources, from sunlight to artificial light. Due to their fluorescence, some rubies may appear more vibrant in daylight and slightly purplish under incandescent light.
The first ruby is natural, with a slightly purplish undertone. In contrast, the second is a synthetic ruby, exceptionally clear under magnification, with an overly perfect, unnaturally bright red color that appears slightly 'off' when held in hand.
Beginner Method
Check The Inclusions
*Real rubies almost always have small inclusions (loupe-clean rubies are extremely rare and very expensive), which are mineral formations that can be seen under magnification.

Natural rubies typically contain a variety of inclusions, such as tiny crystals, silk (fine needle-like inclusions), rutile needles, or color zoning. These inclusions are formed naturally during the gemstone's formation and are often unique to each stone. However, synthetic rubies often contain gas bubbles or flux inclusions, which are not typically found in natural rubies. Gas bubbles are round and can be a clear indication of a synthetic stone created through processes like the Verneuil method.

Check the example below!
The first ruby is a natural, heat-treated specimen from Mozambique. Its inclusions are distinct and display a characteristic natural appearance. In contrast, the second rubies, which are synthetic and round in shape, exhibit inclusions that appear artificial, resembling a hazy cloud with straight, parallel lines. Such a pattern is not found in natural rubies.
Intermediate Method
UV Light Test
Natural and synthetic rubies glow when exposed to ultraviolet light. Some rubies glow less than others (like Thai rubies), but it also doesn't mean they are fake! Usually, synthetic rubies tend to glow more than natural ones. In other words, some rubies glow more depending on their geological formation. (Ex: Burmese ruby will display a strong or medium-strong red color under longwave and shortwave UV light)

Natural rubies often fluoresce under UV light, emitting a red, orange, or sometimes purple glow. This reaction is due to the presence of chromium in the ruby, which causes it to absorb UV light and then re-emit it at a visible wavelength.

Once again, the degree of fluorescence can vary depending on the ruby's origin and the specific trace elements present. For example, rubies from some locations like Myanmar (Burma) are known for strong fluorescence, while others may have a weaker response. Depending on their creation method and additives, synthetic rubies may have a different fluorescent response than natural rubies. Some synthetic rubies may not fluoresce at all, while others may exhibit an intense but distinctly different glow.

Please note that, while useful, the UV light test is not definitive on its own. Some natural rubies may not fluoresce, and some synthetic ones may mimic natural fluorescence. Moreover, treatments like heat treatment can affect a ruby's fluorescent properties.

*Comment: I wouldn't personally use this method to verify the authenticity of any single ruby for sale; instead, I would use it to confirm the authenticity of a large number of rubies that you have purchased in a lot (if all the rubies are told to be from the same mine or origin). Use this method as a complement to the following ones!
Examples of natural rough rubies that are worth between 1000$ - 15000$+
Intermediate Method
Check The Bubbles
These bubbles are formed during the synthetic manufacturing process. In methods like the Verneuil (flame-fusion) process, where powdered chemicals are melted and then cooled to form the crystal, tiny gas bubbles can get trapped inside the stone.

Under a microscope or jeweler's loupe, these bubbles appear as small, round, often spherical inclusions. They can vary in size and are usually scattered throughout the stone. Unlike the natural inclusions found in real rubies, which are typically irregular and include features like silk, rutile needles, or mineral deposits, these synthetic bubbles have a uniform, bubble-like appearance.
The first exhibits an unnatural, slightly "off" pinkish-red hue. Straight, parallel inclusions characterize the second. Meanwhile, the third is impeccably clear, loupe-clean, and possesses a color that mimics natural rubies. However, if its price isn't consistent with that of a flawless natural ruby (which typically exceeds $20,000), it's likely that the ruby is not genuine.
Intermediate Method
Any Certificates?
When purchasing a perfect red ruby that is loupe clean and boasts a great color, obtaining a certificate is essential. It's a standard practice in the gemstone market to accompany such high-quality rubies with a certificate from a reputable gemological laboratory. This certificate attests to the ruby's authenticity, quality, and characteristics. A renowned lab certificate, like GRS, ICA, Gubelin, Bellerophon or Tokyo Gem Lab always accompanies genuine rubies.

The significant value of rubies, which can fetch thousands of dollars per carat, emphasizes the necessity of a certificate. Given this high value, the cost of obtaining a certificate – typically a few hundred dollars – should not be a deterrent for a legitimate seller. In fact, it's a small price to pay for validating the stone's worth and authenticity.

If a seller does not provide a certificate for a high-quality ruby, it should raise a red flag. The absence of certification in such transactions is often suspicious, as it may indicate the ruby's questionable origin or quality. Always insist on a certificate when dealing with expensive gemstones like rubies to ensure you're making a secure and informed purchase.
Natural Rubies (left), GRS Report (Top right), Synthetic rubies (bottom right)
Red Spinel, Red Garnet or Ruby?
When you don't know anything about gemstones, it's difficult to tell the difference between these three stones. It's important to remember that such misunderstandings can be quite common! Even experienced gem dealers have historically confused similar stones; for centuries, red spinels were often mistaken for rubies. A famous example is the Black Prince Ruby, which is actually a red spinel, not a ruby. This kind of mix-up highlights the complexities and challenges of accurately identifying gemstones.

However, here are some examples to assist you in distinguishing between these stones.

Observe the color:

- Ruby: Rubies have a deep red color with a slightly purplish or pinkish hue.
- Red garnet: Red garnets are lighter red, often with a purplish or brownish hue.
- Red spinel: Red spinels have a lighter red color, with a pinkish or orange hue.

Check for inclusions:

- Ruby:
Rubies often have small inclusions, which can be seen using a loupe or magnifying glass.
- Red garnet: Red garnets may have fewer inclusions or a different type of inclusion compared to rubies. Some inclusions help you determine which stone you are holding.
- Red spinel: Red spinels may have fewer inclusions or a different type of inclusion than rubies.
Natural Rubies (left), Red Spinel (bottom right), Synthetic rubies (top right)

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Benjamin Poudevigne
Social Media Manager at GemMatrix
With over ten years of marketing experience, I finally decided to settle down in Bangkok to work in an area that I have always been interested in: the gemstones industry. I'm still learning how the market works on a daily basis, and I enjoy sharing my experience with those who are interested in learning more about gems in general.