Onyx vs. Obsidian – What’s the Difference?

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It’s easy to mistake onyx and obsidian, two of the best-known black gemstones. Both have shiny, polished surfaces and a sleek, deep black appearance, and when used in jewelry, make for intriguing accessories.

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But for all their similarities, onyx and obsidian are two very different gemstones, differing in structure, chemical properties and value, among others.

Here’s a quick rundown of onyx vs. obsidian and the differences you should watch out for before you buy.

What are onyx and obsidian made of?

black onyx pendant
Onyx is the most famous black gemstone. See this here.

Onyx is the most popular black gemstone and has a long and illustrious history as such. Onyx is a type of silicate mineral chalcedony, similar to agate. It’s a layered chalcedony gemstone that forms quite slowly on the surface of the Earth.

Onyx is typically made from black and white bands of silica minerals quartz and moganite, woven together, but it can be solid in color as well. Because of its crystalized structure, it is a mineral.

Round Black Obsidian Gold ring
Obsidian rings set in gold. See this ring here.

Obsidian, on the other hand, is not an actual mineral. It’s actually cooled off volcanic lava that has turned into black volcanic glass. It too is mostly made of silica and it can also have quartz inclusions, although that’s not common. The black color of the obsidian is largely due to the iron and magnesium in it.

Where do onyx and obsidian come from?

Both onyx and obsidian are found in many different places around the globe. Both are localized to specific areas, however, since both require certain conditions to form properly.

Onyx can be found most frequently – in alphabetical order – in Argentina, Australia, Brazil, Canada, China, Czech Republic, Germany, India, Indonesia, Madagascar, Latin America, the UK, the U.S., Uruguay, and Yemen.

Obsidian, on the other hand, can be found in areas with past or present frequent volcanic activity. Such places include Argentina, Armenia, Azerbaijan, Canada, Chile, Georgia, Greece, El Salvador, Guatemala, Iceland, Italy, Japan, Kenya, Mexico, New Zealand, Peru, Scotland, Turkey and the U.S.

What are the physical differences between onyx and obsidian?

So, while onyx is indeed a mineral with a hexagonal crystal system, obsidian is essentially a black volcanic glass. This means that even though the two can look the same, particularly their black variants when they are polished well enough, they are actually very different. The easiest way to differentiate between black onyx and black obsidian is by lifting them up since onyx is significantly denser and heavier than obsidian.

Aside from the significant weight difference, the other main factor that separates black onyx and black obsidian is the fact that the onyx tends to have a slightly duller finish. At the end of the day, it’s a crystal and not glass. However, with a good enough polish, a black onyx can often be given an impressively glassy look, so don’t rely on that alone.

onyx or obsidian?
Onyx or obsidian? Check if you’re right here.

There is also a difference in the type of inclusions that can be seen in these gemstones. Onyx, even the black varities, can often exhibit whitish or greyish whirls and spots that will look like spilled milk inside of the gemstone. Whenever obsidian has white, grey or other colored inclusions, they don’t look like fluid.

However, since both onyx and obsidian can be 100% black, opaque and seemingly deep in their appearance, the weight difference should be your main tell for which is which.

What are the value and price differences between onyx and obsidian?

Both onyx and obsidian are not overly expensive gemstones. In the past, both have been revered by priests, shamans, and even royalty for their beauty and applied spiritual meaning. Today, they’re an affordable gemstone that come in a range of prices.

Both onyx and obsidian have similar price ranges and a beautiful piece of jewelry featuring these stones can be bought for around $50-200. Of course, the jewelry setting and quality of the stone will affect the overall price either way, so bear that in mind when shopping. Here’s an example of an onyx pendant that’s paired with a diamond halo and comes at a relatively high price.

Black obsidian necklace Arrowhead
A high-quality obsidian pendant. See it here.

Overall, onyx tends to be paired with expensive materials like gold, platinum and diamonds and many vintage pieces can be found on the market, all of which adds to its value. Obsidian is generally less expensive and less valuable than onyx.

What types of jewelry can onyx and obsidian be used in?

Despite being different in their contents, onyx and obsidian are often used in similar types of jewelry because of their appearance and durability. They can both be used in anything from rings and earrings, through bracelets to pendants and necklaces. Because onyx is heavier than obsidian, it’s typically used in smaller pieces. Both make for lovely decorations and ornaments, however, and contribute to a rather mystical and spiritual feel on any piece of jewelry.

Because of their relatively low prices, both onyx and obsidian are rarely part of luxurious jewelry collections, unless they’ve been used as special side pieces for their unique look. This ring is an excellent example where onyx is used to bring out the beauty of the diamond in a stunning way.

However, in everyday jewelry pieces, both onyx and obsidian are quite popular. They are also frequently used as ornaments in various artisan creations such as frames, vases, statues, clocks, and other such items. Because of their perceived spiritual attributes, both onyx and obsidian are frequently used as healing stones as well.

What are the spiritual meanings of onyx and obsidian?

The reason both obsidian and onyx were so highly valued in the past lies largely in their prescribed spiritual qualities. Despite the two gemstones’ recent drop in overall price, a lot of people who still value such factors rate onyx and obsidian – particularly their black variants – very highly.

Obsidian, also known as the “psychic vacuum cleaner,” is beloved for its intense and mysterious vibes. It’s believed to be able to deliver a deep and comprehensive psychic cleansing to anyone who keeps an obsidian stone by their side. It’s essentially viewed as a spiritual maid service – it cleans your mind, soul, heart, and auras of any negative notions and emotions, plus, it also protects you against their future inceptions. The so called “shadow traits” such as anger, fear, anxiety, addition, and others, all are believed to be treated by obsidian stones.

Onyx, on the other hand, is viewed as a powerful “warrior’s stone”. It’s believed to be a strong and sturdy companion to anyone’s journey as it is capable of stomping out negative thoughts and notions, with fear being the onyx’s most frequent victim. In Peruvian and Native American cultures, the onyx crystal is meant to symbolize initiation and change. There, it inspires the feeling of personal growth and power, the type of personal development that’s achieved by facing one’s fears.

As you can see, both onyx and obsidian have rather similar spiritual meanings and symbolic perceptions. That’s likely not an accident. Because both have very deep and opaque appearances, resembling a bottomless pit when cut and polished right, they can leave the impression of being stones you can “drop your negativity in”, never to see it again.

*Disclaimer: Jewelry Shopping Guide does not guarantee or validate any of the claims related to the metaphysical and alternative healing powers of this or any other gemstone. This information should in no way be used as a substitute for medical advice.

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Where to buy onyx and obsidian jewelry?

While onyx is more of a mainstream gemstone, finding obsidian at your nearby brick and mortar shop can prove more difficult. We suggest searching online for more options and competitive pricing.

You can find beautiful onyx and obsidian jewelry at a range of prices to suit any budget on artisan stores like Etsy and Amazon. Ensure that the retailer is reputable and communicates with you effectively and honestly about their jewelry. Your vendor should disclose any information about treatments and enhancements to you honestly.

Always check the after sales service and returns policy, in case of any issues.

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