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Onyx Stone, Meaning and Healing Properties


1. What is Onyx?
2. What is Black Onyx?
3. Onyx or Calcite?
4. So Much Confusion
5. Onyx Healing Properties
6. Article Photos
7. Shop Onyx

What is Onyx?

Onyx is a natural mineral that's used for a variety of purposes.

As well as for gemstones, onyx is used for fireplace surrounds, household furniture and various ornaments.

There is a great deal of confusion regarding the correct use of the name 'onyx'.  In the vast majority of cases, it's used incorrectly. 

Regarding this mineral's colour, onyx is a black and white, banded variety of agate.  It can also be a single-coloured agate with alternating shades of light and darker-coloured bands.

Although onyx and agate are both varieties of the mineral chalcedony, the main difference is the bands in onyx are parallel, whereas in agate they're curved. 

What is Black Onyx?

Most black onyx being sold is either black agate or black chalcedony.  Natural black onyx is quite rare.

Throughout history, the vast majority of black onyx has been dyed.  In one respected gemstone reference it's stated that in order to achieve the black colour, stones are soaked in sugar or honey before being treated with sulphuric acid.

In his encyclopedia, Naturalis Historia [circa 77-79 AD] the ancient Roman author and naturalist Pliny the Elder speaks at length about techniques used to change the colour of one gemstone to make it look like another.

"There is considerable difficulty in distinguishing genuine stones from false; the more so, as there has been discovered a method of transforming genuine stones of one kind into false stones of another.

Sardonyx, for example, is imitated by cementing together three other precious stones, in such a way that no skill can detect the fraud; a black stone being used for the purpose, a white stone, and one of a vermilion colour, each of them, in its own way, a stone of high repute.

Nay, even more than this, there are books in existence, the authors of which I forbear to name, which give instructions how to stain crystal in such a way as to imitate smaragdus and other transparent stones, how to make sardonyx of sarda, and other gems in a similar manner.

Indeed, there is no kind of fraud practised, by which larger profits are made."

Ref; (Pliny's Naturalis Historia chapter 75). Please Note.

Some History of Onyx

The history of onyx can be traced back further than ancient Rome.  It's mentioned numerous times in the Bible and is said to have been one of the gemstones in the high priest breastplate.

This biblical garment was worn by Aaron, the first Jewish high priest, over a tunic-like garment.

Onyx is said to have been the second stone in the fourth row.  To its left was a beryl, and to its right a jasper.
Much of the 'onyx' used for decorative purposes, so items like chess sets, figurines, tumbled stones and gemstones, is banded calcite.  The stone in the image above is a perfect example.

Calcite is often used instead of onyx because it's more readily available.  It's also much softer which makes it an easier stone to work with.

According to the traditional birthstone chart, ruby is the birthstone for July but onyx can be used as an alternative.

Onyx or Calcite?

It can be difficult to tell onyx from calcite on sight alone.  The simplest way to identify one from the other is to do a scratch or an acid test.

The problem with both is that some damage will be caused.

On the Mohs scale of hardness, onyx grades 6.5 to 7, calcite grades 3.  Therefore, calcite will be much easier to scratch.

To establish whether a stone is calcite, try scratching it with fluorite or a feldspar mineral such as labradorite, amazonite, moonstone or sunstone.  Alternatively, you could use a piece of window glass or a metal knife (a regular knife used for eating).

These materials are all harder than calcite but softer than onyx.

With onyx being relatively hard, it's a difficult stone to scratch.  The mineral quartz which grades 7 on the Mohs scale, may scratch it, but corundum, topaz and diamond will definitely scratch it.

Hardness should not be confused with toughness.  One refers to the resistance of one mineral to be scratched by another, and the other refers to a mineral's resistance to cracking, chipping, pressure or breaking.  
banded calcite sphere An acid test is another way to determine whether a mineral is calcite or onyx. 

Calcite is the crystalline form of calcium carbonate.  Add a drop of acid to calcite and it will effervesce (fizz).  This is because of a chemical reaction between the acid and the carbonate ions in calcite.  Vinegar can be used for this test. 

At the point where the acid makes contact with the stone, if it's calcite or another calcium carbonate mineral you'll see tiny bubbles.  You'll have to look closely, you may have to use a magnifier. If it's onyx it will not effervesce.

Any stone that's not black and has light-coloured alternating parallel bands is likely to be calcite, chalcedony, agate or any number of other minerals.

So Much Confusion

The name onyx is used to describe a banded variety of chalcedony.  The mineral chalcedony can include many different types of quartz.

Terminology can be ambiguous, and the translation of names into different languages, especially over hundreds or thousands of years can also complicate matters.

In historical texts, lapis lazuli was often mistaken for sapphire because in the ancient world, it was called sapphirus.

Determining the exact characteristics of some minerals can be subjective and open to interpretation. Geologists often have different criteria and perspectives when defining onyx which can lead to disagreements and debates.

The use of trade names to popularise rocks and minerals can also cause confusion.  Many stones that have been given a name that ends with 'Jasper' do not contain jasper at all.  An example is Dalmatian Jasper

Limestone onyx is a trade name for limestone that can look similar to onyx.

'Green onyx' and the green banded stone that many people call onyx are agate or calcite.  They're usually dyed.

Material from Pakistan marketed as 'onyx' or 'onyx marble', is travertine.  This stone is made up of colourful bands of calcite.

Onyx Healing Properties

When used as a healing crystal, onyx provides strength and support, especially in difficult and stressful situations.  It can help you be the master of your own destiny and promotes vigour, stamina and determination.

Onyx holds onto memories so they can be used to explore past lives.  It's a comforting stone for those dealing with grief.  It can also be used to strengthen self-control and to stimulate the power of good decision-making.

It boosts self-confidence, helps ease the fear associated with phobias, and balances yin and yang energies.

In ancient times, warriors were said to have carried onyx because they believed it would bring courage and protect them from harm. Today it's worn or carried to protect against dark forces and promote a sense of security.

Onyx can help release negative emotions and past trauma. This allows you to heal and move forward. It promotes self-control and discipline which can help ease addictive patterns of behaviour and destructive habits.

Onyx is a stone for the present but one that carries with it happy and positive memories from the past.

Article Pictures

We're grateful to have permission from several photographers to use their work on our website.  Despite this, it was extremely difficult to find photos of natural onyx.

Most material labelled as 'onyx' is calcite, or contains a significant percentage of calcite.

The image at the top of our article is natural onyx.  Photo courtesy of Stan Celestian.  It's clickable and redirects to the original image.

Pop-up images; The rootbeer calcite (from Payson, Arizona) is also courtesy of Stan Celestian.  The dalmatian jasper tumbled stones are from our collection.  

Here's another two photos of onyx.  We've linked to them because we've not been able to get permission to use them on our website; 

The other two photos in our article are banded calcite.  The rectangular gemstone is from our collection.

shop now explore our collection of onyx
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