Sardonyx is banded chalcedony: red-brown sard layers with black or white. Much of it is dyed, and has been since Roman times. We do not carry it. Onyx and black onyx are the nearest stones we do.
Silicate (quartz, chalcedony) · onyx (banded chalcedony)
Sardonyx
Sardónice
- Palette
- Red Brown White Black
- Mined in
- Brazil, India, Japan, Turkey, United States
- Hardness
- Mohs 6.0–7.0 ?
- See-through
- translucent
- Known since
- Prehistoric
- Named for
- onyx (Greek for fingernail) banded with red-brown sard
- Intention
- Protection Strength
- Looking for
- Courage Protection Focus and clarity Luck
- Water
- Keep it dry; wipe with a soft cloth
- Dye or finish
- Sardonyx beads are often dyed to deepen the red and black bands, and chemical or heat color change is common. Dealers list the color as dye enhanced.
Not in our pieces now
GEMMA AUGUSTEA
The Gemma Augustea, a Roman cameo from about AD 9 to 12, is carved from a two-layered onyx measuring 19 by 23 centimeters.
SECOND DYNASTY
Banded onyx, the sardonyx family, was already being made into bowls and pottery items in Egypt by the Second Dynasty.
FINGERNAIL
Onyx comes from a Greek word for 'claw' or 'fingernail,' and the pink and white bands can look like one; sardonyx swaps the black bands for red sard.
What it is
Straight bands of red to brown sard alternating with white or black onyx, polished smooth and opaque to translucent. It is banded chalcedony, a fine-grained quartz. Much of the red and black on the market is dye or a heat-and-chemical color change, so a very bold, even band is often a dyed stone.
What gives it its color
Sardonyx is banded chalcedony with reddish-brown sard bands colored by iron oxide alongside white or black bands, and much of the red is deepened by dyeing or heating.
In history
Scipio Africanus (236-183 BC) was the first Roman to wear sardonyx, and it became a favorite for signet rings because it did not carry away the sealing wax. A sardonyx ring that Polycrates of Samos threw into the sea around 540 BC was later shown in Rome in the Temple of Concord, set in a golden horn, though even Roman writers doubted it was the original.
What's said about it
In crystal lore today, sardonyx is the stone people keep for focus, luck and steady confidence. It is linked with the root and sacral chakras, the low, grounded part of the body.
Roman soldiers carried sardonyx amulets engraved with Mars for courage, and Romans prized it as a signet stone. In older lists it is an August birthstone.
People carry it in a pants pocket, or tape a piece under a study chair.
How people wear or keep it: In a pants pocket, taped under a study chair, or on the wrist.
In crystal practice
In the crystal tradition, sardonyx is paired with the root and sacral chakras, so practitioners rest it there during meditation or lie down with it in place for a few quiet minutes. Day to day, the same tradition suggests keeping it close: in a pants pocket, taped under a study chair, on the wrist. People reach for it when they want courage, protection, focus and clarity, and many set an intention when they put it on. Most practitioners cleanse a new stone first (running water only if the stone can take it, otherwise smoke or moonlight) and set it aside now and then to rest.
These are beliefs people have held and still hold about the stone, reported as such. Nothing here is a promise or a medical claim. We sell stones as jewelry, not for these effects.
Associations
The chakra and star sign this stone is usually matched with. These are popular traditions, not facts about the stone.
ChakraRoot, Sacral
ZodiacAries, Leo
BirthstoneAugust
ElementFire
Care
- Chalcedony is hard (Mohs 6 to 7), but a hard knock can still chip the edge of a bead. Store it apart from rougher stones.
- Much sardonyx is dyed, so avoid long soaks, solvents and harsh cleaners, which can dull the color.
- Wipe with a soft damp cloth and dry it; skip ultrasonic cleaners if you are not sure whether it was dyed.
- Take it off before swimming or using hand sanitizer.
- Keep it in a pouch or box of its own so the polish stays even.
How to tell what you have
- Real sardonyx is hard (6.5 to 7 on the Mohs scale) banded chalcedony with straight parallel bands; calcite sold as onyx is much softer and fizzes in acid.
- Very bold, even red and black bands are usually enhanced. Check the drill hole and cracks for dye build-up.
What sets the price
The price follows how sharp and straight the bands are against each other, whether the red and black are natural or dyed, and the bead size, roundness and polish; calcite sold as onyx is a softer, different stone.
Rules and sourcing
Sardonyx beads are often dyed to deepen the red and black bands. The FTC jewelry guides call for a seller to disclose added color.
Questions people ask at our table
What is sardonyx?
Banded chalcedony with red-brown sard layers alternating with white or black onyx layers. It is a variety of the same quartz family as agate and carnelian.
Is sardonyx natural or dyed?
Natural sardonyx exists, but most of the red and black in commerce is dye or a color change by chemical and heat methods. Roman writers already complained about fakes made by dyeing a sard or gluing three stones together.
Is it a birthstone?
It appears as an August stone in traditional birthstone lists, alongside carnelian. Some older lists place it in other months.
How do I tell it from banded calcite sold as onyx?
Banded calcite, often sold as Mexican or cave onyx, is much softer than true onyx and sardonyx, so a key scratches it. Sardonyx is chalcedony, a hard quartz.
Do you carry sardonyx?
No. The closest stones we carry are onyx, black onyx and red network.
Not in our pieces right now
Stones we do carry that are close to it are listed under related stones.
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