Onyx Jewelry in Bangkok

Black onyx is the deep, glossy black stone of signet rings, cufflinks and classic men’s jewelry. It takes a mirror polish, it is hard enough for daily wear, and it gives a clean, bold contrast against silver or gold. Onyx has been carved and worn since ancient Rome, and it still looks modern today. We set natural onyx in 925 sterling silver and solid gold at our studio on Sukhumvit 71, Bangkok.

This page covers what onyx is, how its black color is made, how it compares with other black gems, how to wear and care for it, what makes a good stone, where it comes from, how to see the stones at our shop, and how to order in Bangkok or anywhere in Thailand.

What onyx is

Onyx is a form of chalcedony, a variety of quartz made of crystals far too small to see. Strictly, onyx is chalcedony with straight, parallel bands, usually black and white. When the bands are red or brown and white it is called sardonyx. These banded stones are the classic material for cameos, where an artist carves a white figure that stands out against a dark layer.

The solid black onyx used in most jewelry today is a little different, and we want to be clear about it. Pure, even black chalcedony is very rare in nature. Almost all black onyx is natural gray or banded chalcedony that has been dyed black. The stone is porous, so it is soaked in a sugar solution and then treated with acid, which turns the sugar into carbon deep inside the stone, or colored with modern dyes. This has been done since Roman times, it is permanent, and it is a long-standing accepted treatment in the trade.

So the stone is natural chalcedony and its color is almost always the result of dyeing. Every stone we set is natural, and we tell you before you order if a stone has been dyed or treated in any way.

Onyx facts at a glance

• Color: solid jet black, or black and white in bands
• Hardness: 6.5 to 7 on the Mohs scale
• Family: chalcedony, a form of quartz
• Treatment: black onyx is almost always dyed, a permanent and accepted practice we disclose
• Best for: signet rings, men’s rings, cufflinks, pendants and inlay
• Care: warm soapy water and a soft cloth; avoid harsh chemicals
• Price: depends on the quality and carat you choose; we quote before you order

Onyx and other black gems

Black spinel is harder at 8 and has a natural black color with no treatment. It is usually faceted, so it sparkles, while onyx is usually polished flat or as a smooth dome for a deep, glossy look. Choose spinel for shine and onyx for a calm, solid black.

Black tourmaline, also called schorl, is a natural black crystal at 7 to 7.5 on the Mohs scale. It is less glossy and is used more often in casual jewelry.

Black diamond is far harder and costs much more. Onyx gives a similar bold black in larger shapes for a much smaller budget.

Jet and obsidian are other traditional black materials. Jet is fossilized wood and much softer, and obsidian is volcanic glass that chips easily. Onyx is harder and more durable than both.

Lapis lazuli is another opaque stone with a long history. It is deep blue rather than black, often with gold flecks of pyrite, and it suits the same simple, bold settings as onyx.

How to wear and care for onyx

At 6.5 to 7 on the Mohs scale, onyx is fine for rings, pendants and cufflinks worn often. Its flat, polished surface can show fine scratches over the years on a ring worn every day, and a hard knock can chip an edge, so take it off for the gym and heavy work. A bezel setting protects the edges of a flat onyx top.

Clean it in warm soapy water with a soft cloth, then dry it. Keep it away from strong acids, solvents and household cleaners, and do not soak it for long. A soft cloth brings back the shine of a polished surface. If it ever needs a polish or a check of the setting, bring it to our shop. Maintenance is free on jewelry we made.

What makes a good onyx

Color should be an even, deep black with no gray patches, brown spots or streaks when you look at it in daylight.

Polish is what makes onyx beautiful. A good stone has a smooth, mirror-like surface with no pits, scratches or dull areas.

Soundness matters for flat tops and inlay. Look for a stone with no cracks or chips along the edges.

Cut and shape finish the picture. Onyx is cut as flat tablets for signet rings, smooth domes, beads and faceted stones. For banded onyx, even, straight bands with good contrast are the most valued.

Where onyx comes from

Chalcedony for onyx comes mainly from Brazil, Uruguay and India, with more from Madagascar, Mexico and other countries. Much of the world’s dyeing of chalcedony grew up in Idar-Oberstein in Germany, a historic center of stone cutting. If you want to know the origin of a particular stone, ask us: we offer certified stones, and an uncertified stone can be sent to a gem lab for a report at extra cost.

See onyx at our shop in Bangkok

With onyx it comes down to polish and evenness. A good one is deep black with no gray patches or brown streaks in daylight, with a mirror surface free of pits, easiest to check in your hand. Say onyx as you book and more will be ready, as flat tablets for signet rings, smooth domes, beads and faceted stones.

Walk in any time we are open, or book ahead so Yaron is there to help with the stone, the design and the metal, from 925 silver and gold plating to solid 9K, 14K or 18K gold.

A flat onyx tablet starts a signet ring or cufflinks, so you may want to pick it before the design. Buy it loose with no jewelry order, and we would be very happy to make the piece.

Not in Bangkok? Message us and we will send photos and prices of the onyx we have.

Onyx questions we get

Is your onyx natural?

The stone is natural chalcedony, but almost all black onyx in the world is dyed to get its even black color. This is a long-standing and permanent accepted treatment, and we tell you before you order. We are a member of the Thai Gem and Jewelry Traders Association.

Will the black color of onyx fade?

No. The color sits deep inside the stone and is permanent in normal wear. Keep it away from strong acids and harsh cleaners to protect the polish.

What is the difference between onyx and black spinel?

Onyx is chalcedony, usually dyed and polished smooth for a glossy black. Black spinel is a harder, naturally black stone, usually faceted so it sparkles.

Is onyx good for a men’s ring?

Yes. Onyx is the classic stone for signet rings and men’s rings. At 6.5 to 7 on the Mohs scale it wears well, and a bezel setting protects its edges.

How much does onyx jewelry cost?

It depends on the quality and carat of the stone you choose, and on the metal. We give you the price before anything is made.

Can I buy just the stone?

Yes. We sell onyx on its own, so you can take the stone home and decide about jewelry later. If you would like it made into a ring or cufflinks, we are happy to set it now or later.

How long does an onyx piece take?

7 to 10 working days from your order, because the stones are already here in our shop, then 1 to 3 working days for delivery inside Thailand. We also ship abroad by FedEx.

Every onyx piece is made to order by our team in Bangkok in 925 sterling silver or solid gold, with a 3-year warranty, free maintenance and free shipping across Thailand.