How To Tell If Black Onyx Is Real or Not?

Black onyx is a semi-precious stone that has been used in jewelry and other decorative items for centuries. It is one kind of chalcedony, which is a form of quartz. Black onyx gets its name from the Greek word for “claw,” which is onyx. The stone is found in a variety of colors, but the most popular is black. It is believed to have healing properties and is often used in alternative medicine.

Nowadays, people struggle to find genuine Black onyx because of a lack of Knowledge. Here in this guide, we will discuss how to tell if black is real or not.


How To Tell If Black Onyx Is Real?

 When determining if black onyx is real, it is essential to consider the weight of the stone and its overall appearance. Black onyx is a very dense stone, so it should feel heavy in hand. The surface of black onyx should be smooth and glassy, with a high polish. If the stone is chipped or dull in appearance, it is likely not real onyx

The following are some signs that your black onyx is real.

A smooth and reflective surface

If the gemstone has a polished, smooth, and reflective surface, you can tell it is a real black onyx. As we mentioned above, there should be no cracks, scratches, or foggy surfaces. 

A real black onyx has an entirely spotless and smooth exterior. So, before you buy, you should carefully check its surface. 

Keep in mind that not all black onyx stones are 100% black; some may come with parallel and vertical bands. 


Another determining factor that your black onyx is genuine is its cost. Black onyx is more valuable compared to other onyx stones like red, blue, or yellow specimens. 

The price of black onyx per carat is about 1 dollar to 500 dollars. The cost range moves based on the setting of the stone. 

For example, a gold setting is more expensive compared to black onyx with a silver setting. Therefore, the gemstone is valuable, and its high value is due to its combination with gold. Additionally, it also has high significance in the world of crystals. 

If you found black onyx stones not associated with gold or silver, the cost range may not be that pricey. The price can also depend on the quantity and size of the stone. 


Black onyx has a score of 7 on the Mohs scale of hardness. So, based on the Mohs Hardness Scale chart, a real black onyx can’t be scratched by a glass plate or knife. 

So, if you try to scratch the stone with a knife but still intact, it’s a real one. However, apply this method if you have lots of black onyx tumble stones from the store to test their authenticity. 

High heat tolerance

If a black onyx is real, it can tolerate high-temperature levels. You may apply this testing method if you buy a bunch of the stones in one store. 

You may use your lighter to light a portion of the black onyx stone for 10 seconds. Then, immediately drop the stone in a bowl of water. It will remain intact and safe if it’s real.

On the other hand, if your black onyx is fake, you will observe the part where your light was melted. So ensure the gemstone is cool before getting it from your water container. 


It is also essential to consider the retailer where you purchase your black onyx stones. If you buy online, you can check the stars’ ratings, reviews, and information about the retailer. 

Make sure to buy from a reliable online store to get genuine black onyx. A well-experienced and credible retailer knows all the answers to your questions about a specific crystal. 

They can also give you evidence of the authenticity of your purchased black onyx stone. You can ask the retailer for the documents that they obtained the stones. 

What is black onyx?

The black onyx is a jewel with opaque transparency and a waxy luster. It is considered among the rarest onyx stone varieties. 

One interesting fact about black onyx is that it was believed to have a demon trapped inside it. Based on legends, the black onyx only releases the demon at night. Then, it will cause havoc and sow discord seed among people, especially couples. 

However, the myth above wasn’t the only one associated with the stone. It is also believed that individuals who regularly wear authentic black onyx jewelry like pendants and rings can store memories and replay them through the psychometrics process. 

The black onyx stone has 6.5 to 7 hardness on the Mohs scale, so it is best for beads and carved gemstones. 

What are some tests to know that black onyx is real? 

If you want to know if your black onyx is real, you can perform the following tests. 

Breath test

Hold your black onyx close to your mouth and breathe on the stone. Your jewel can be fake if it takes more than 3 seconds to clear up. 

Newspaper test

Put your black onyx above the newspaper and try to read the words under it. If you succeed, then your gemstone is a fake one. 

Touch test

Try gently touching the stone’s surface with a pad of your finger. If it feels warm against your skin, your jewel can be a fake one and is made from glass. 

Comparison test 

Hold the black onyx next to black glass, then compare them. If they exactly look alike, you may have a fake stone. 

Can you wear a black onyx ring in the shower? 

You should avoid wearing your black onyx ring as you take a shower. Thus, the chemicals from your shower products can damage the black onyx surface. 

In addition, the cleanser’s soapy texture can loosen your ring. It will fall off your fingers and can be damaged as it hits the ground. 


Usually, glass and onyx are misidentified as one another. However, you can tell the difference between the two by putting the piece near your lips. If it starts to feel warm, it can be a glass. 

Get a small piece from the black onyx jewel and put it inside a covering in a safe area. Then, gently break the work using a hammer. If the broken pieces are shiny than dull, they can be made from glass material.

Frequently asked questions


Yes, you can wear your black onyx ring under the sun.


It is not recommended to wear your black onyx ring since you may accidentally knock the gemstone against a hard surface and damage it. 


A black onyx doesn’t scratch easily. It is a highly durable and low-maintenance stone. You should carefully store it in a pouch or box if not used. 


You should also keep it away from harsh chemicals. It would help if you were responsible for your jewel’s proper care and cleaning. With this, your stone can last for many years. 


Well, it is not a precious gemstone. However, the black onyx is a semi-precious gem. 


Usually, black onyx is used to protect against negative energy. The gemstone is considered a master of good fortune. The black onyx is believed to have solid healing properties that can shield you from things that can bring harm. 


To summarize, a genuine black onyx comes with a waxy luster and opaque transparency. As a result, it has a glossy appearance when polished. On the other hand, a fake black onyx looks shiny like glass. 

If you want your black onyx jewelry to last for many years, you should be responsible for its proper care and maintenance. Do you love wearing gemstones? If yes, you can check out our post about the best yellow gemstones.

1 thought on “How To Tell If Black Onyx Is Real or Not?”

Leave a Comment