Learn about the Gemstone Onyx and its use in Jewelry

Onyx is also known as veined agate (agate is also a variety of a rock-forming mineral almost similar to onyx) and a variety of a rock-forming mineral called chalcedony. The origin of the word comes from the Latin word of the same spelling, which means “claw” or “fingernail.” White bands and flesh-colored onyx sometimes resemble a fingernail, hence the name. 

The gemstone is considered the birthstone for December and the birthstone for the Zodiac signs Leo and Capricorn. 

History of the Gemstone

The row of nature black onyx macro shot isolated

Onyx, as mentioned above, is a type of chalcedony, which is itself a form of microcrystalline quartz. Chalcedony is a type of quartz, and therefore onyx comes from the family of chalcedony-quartz. This means that onyx is composed of tiny crystal grains that are not visible to the naked eye. 

Some references say that Onyx is properly applied as a striped, semiprecious variety of agate with white and black alternating bands. Onyx, whether as a variety or sub-variety, is still chalcedony. Natural types of Onyx come from India and South America. It is formed from the deposition of silica at low temperatures from silica-rich waters permeating through cracks and cracks in other rocks. Onyx is prevalent for carved cameos and intaglios because its coatings can be cut to show a color contrast. 

For centuries, onyx has been cherished across Asia, North North America, and South America and traded as a valuable stone in all parts of the earth. In the Victorian Grand Period, around 1861-1885, onyx was a popular gemstone as mourning jewelry. Over time, this stone has accumulated a dark and sinister body of folklore and legends. 

Mythological Stories about Onyx

Gemstones seem to be always connected with mythological stories. As for Onyx, the gemstone is connected with a story of the Goddess Venus, Queen Cleopatra, and a demon. 

According to the myth, while the Goddess Venus was sleeping, her son Eros cut her fingernails and left clippings scattered on the ground. Another version said that Eros tried to shoot his mother with one of his love arrows that cut through her fingernails. The fingernails fell from Mount Olympus to the mortal Indus River and became the divine stones that are now called Onyx. 

Another mythological story about the gemstone is regarding its color. Most of the onyx we know today comes in black, which results from its ability to absorb negative energy. It is said that the darker the color of the gemstone, the more negative energy it has absorbed. Queen Cleopatra (a character in the Julius Caesar drama) of Egypt is said to possess a piece of jewelry made of Onyx to alert her to incoming dangers. 

The third story of the gemstone is about a legend. Ancient ancestors believed that onyx had a demon confined within that would awaken at night, sowing disharmony, particularly between lovers.   

Where They Are Mined 

The gemstone occurs across the globe. A notable source of Onyx includes India, Egypt, China, Mexico, Madagascar, Italy, Germany, Australia, Brazil, Canada, the Czech Republic, France, Indonesia, Russia, Scotland, the United Kingdom, the United States, Uruguay, and Yemen. 

Popular Usage 

gold earrings with onyx and diamonds on a white background. Long earrings. women's accessories

Onyx has been used as early as the second dynasty in pottery items and bowls. 

Brazilian Green Onyx has been used heavily throughout sculptures, dishes in Austria, and art decorations, particularly during the 1930s and 1940s. 

Metaphysical characteristics include the ability to provide concentration, make a person calm and worry-free, and reduce stress and anxiety.

Onyx makes a durable jewelry stone. They can resist scratching from household dust, which is one of the most common hazards of everyday wear. They can resist chips and physical blows very well as they have a tough tenacity (describes the measure of a material’s resistance to blows) and no cleavage (refers to a break in a crystal along internal planes). The black color and opaque appearance of Onyx has been utilized since the Victorian times as a foil to translucent colored gems and diamonds in a variety of pieces.  

Some contemporary jewelers seized the stark appearance and polished luster of the gemstone to make them center stones. The material has a flat surface that shows an extraordinary gloss. 

Chemical Composition

Onyx’s chemical formula is silicon dioxide. It is formed of bands of alternating colors of chalcedony. The gemstone is primarily called an agate because of its similar banding, except that agate has a more chaotic banding.

On the Mohs scale, which measures the hardness of gemstones, onyx is rated at 7, which is a rate that is not too hard and is good for carving. 

Color and Size

Onyx is usually black. But it has a wide variety of other colors that have been categorized as its types. A type of Onyx that is red is called Sardonyx. Other types of Onyx include Carnelian Onyx gemstone, White Onyx gemstone, Blue Onyx gemstone, and Black Onyx gemstone. Onyx can form in mass several pounds in weight and many inches in diameter just like other chalcedonies. 


Natural black onyx is rare. Commercially dyed or other forms of chalcedony, particularly agate dyed to look like natural black onyx, are the most common types of onyx found in the market. Other color varieties exist and are widely available in the market. 

Interesting Facts 

  • Ancient Indian and Persian tales referred to Onyx as a protector from evil. 
  • Warriors of ancient Romans wore sardonic amulets (which include onyx substance) in war as they believe the amulets featured the God of War, who give them the courage to fight.  
  • Onyx was used in ancient Persia to treat epilepsy. 
  • Ancient China believes that whoever wears Onyx is provided with determination and stamina. 
  • Although the gemstone has been connected with dull and dark stories, ancestors from different countries believed that Onyx helps deal with grief, loss, and death. 
  • Onyx necklaces allegedly decrease feelings of lust. 

General Cost

Onyx is a relatively inexpensive gemstone. The size and quality of the stone have a huge effect on its cost, which can range from $1 to $500 per carat or more. Black onyx, however, is its most expensive variety. The high price of black onyx comes from the style and craftsmanship of the jewelry itself. Complicated cuts and custom settings increase the price of a piece of black onyx jewelry. 


Although Onyx has been associated with somber and dark stories, most cultures believe that its dark history made it an absorber of negative energies. Today it can be found in popular jewelry because of its striking color.