Are you aching to differentiate a real ruby from a fake ruby? Ruby is part of the top three in the gemstone world, and rubies in general command high prices. It would be unfortunate if you buy faux rubies instead of the genuine article.

Rubies and sapphires are from the same family of mineral – corundum. It is the internal inclusions that change the color of corundum to red (for rubies) and various hues of blue for a sapphire.

Different chemical impurities in corundum can also produce colors such as yellow, green, orange, etc. These slight changes create the spectrum of corundum gemstones that we so love. But how do you know that the gem in front of you is a real ruby? Let’s find out.

How to Tell if Ruby is Real?


The ruby’s stunning color is the first facet of this gemstone that you should learn to evaluate. The primary hue for this corundum species is red—nothing more, nothing less. There is no green ruby or blue ruby – rubies are red, full stop. Secondary hues may be present in rubies, but they remain dominated by the deep red (almost blood red, some experts say).

Expect faint outlines of purple or sometimes orange in some specimens of the ruby. There will be times when the secondary color present in rubies will sometimes offset the primary one. You are free to choose what type of ruby you would like to bring home.

As for simulants and fake rubies, these will likely produce a faint or even dull rendition of crystal red when you take a closer look. When you place a real ruby beside a simulant, you’ll see the vast difference in color quality immediately. It’s difficult  to copy the exact color of gems found in nature.


Like other genuine gemstones, the clarity or brightness of a ruby specimen when hit by light is not reduced by the presence of visible inclusions inside the crystalline structure.

There is even one type of ruby called the star ruby that is famous for its internal inclusions. Clarity is superb with genuine rubies, while the fake ones will likely underperform when exposed to any light. Again, a side by side comparison will reveal the fake one quickly.

If you don’t have a certified ruby to compare a possible faux ruby, observe how the internal structures stand out when you examine the stone with some light. A real ruby will reveal not only the beauty of its facets but also its inclusions and other imperfections that go beyond the surface of the gemstone.

Is It Glass?

Some unscrupulous manufacturers pass of plain glass as rubies. This is done by staining the glass or adding pigments to it during the blowing process.

But like we’ve said before, approximating the clarity and color of real rubies is next to impossible. Faux rubies made of glass will look like glass, period. glass may scintillate some light, but its ability to do so will be far less exciting than what a genuine ruby can do with light.

Check for dullness and fogginess in the material, as well as the lack of luster when you rotate and angle the gemstone against a source of light. It’s also useful to remember that rubies have red so deep that if you look at one intently in the presence of natural light, it’s like looking straight at a bright red stoplight.

Can You Scratch It?

This is a standard durability test where faux rubies cannot hide. If you are allowed to do so (assuming that you have not purchased the ruby yet), grab a small coin and scratch the ruby’s surface. Do you see tiny bits being scraped off? Do you see an angry scratch where the coin rubbed against the material?

If you do, then you are likely looking at a faux ruby rather than the real thing. The reason for this is that rubies are hard minerals, and they can’t easily be scratched even with a hard coin. They’re not supposed to show any damage or even dulling across their facets, especially if it’s just a coin or a kitchen knife. So if you see some damage, the jeweler who sold the ruby to you has plenty of explaining.

Another method is to use ruby to scratch something. If the gemstone you are holding can easily scratch glass without visible damage, then you are likely in the presence of a real gem. On the other hand, if the ruby rubs off on the glass, then the “ruby” is softer than glass (which has a Mohs hardness rating of 5), and it’s likely a fake.

Is It One Of These Simulants?

Ruby simulants abound in the market, and knowledge of these simulants might save you from a lot of heartaches when shopping for jewelry.

The most common ruby simulant is garnet, which is duller than ruby, color-wise. Garnet is also a silicate mineral. In terms of durability, garnets rank lower in the Mohs scale of hardness so that you can scratch a garnet with a ruby, technically. Tourmaline is another natural simulant of the ruby.

The dead giveaway is the presence of pink, which usually combines well with the bright red of tourmaline specimens. Tourmaline ranks higher than garnet in terms of hardness, but ruby is still a harder mineral by far.

Glass simulants might look the part if they are machine-cut, but they also fail in terms of the hardness test because they’re just glass. If you drop a glass simulant, it will likely crack or, worse, shatter.

Glass simulants will fail the fire test (lighting a crystal briefly and dropping it in ice-cold water) because that is how glass behaves when there are extremely hot and cold extremes. Hard minerals will show no cracking because the Earth forges them under extreme temperatures and unbelievable pressures.