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Sardonyx meaning and properties

Sardonyx is the stone of the fingernail in tradition: a brown-red and white band, cited since Antiquity.

  • Loyalty
  • Humility
  • Ribbon
The essentials

Sardonyx at a glance

For you, a red and white ribbon to wear as a reminder of loyalty to loved ones, and humility in success.

A question to ask yourself

To which faithful person would you like to say thank you with a small object?

Something to watch

A sudden change in temperature can crack it: no direct heat source.

Color
red, brown, white
Associated intentions
confidence, protection
Birthstone
August (1912 list)
Type
mineral
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What it evokes

In tradition, sardonyx is the stone of humility and loyalty, and recent books credit it with confidence and protection.

Its name tells its image: Pliny explains that sardonyx was a red sard bearing a white part, as the nail rests on the flesh. In the Middle Ages, Rabanus Maurus reads in it the humility of the saints despite their merits, and, according to Flavius Josephus, the two sardonyxes that adorned Aaron’s shoulders represent the sun and the moon. Pliny credits Scipio Africanus with being the first to wear a sardonyx in Rome.

It serves as a seal or a marker.

The traditions

  1. Rome, 1st century

    Pliny writes that sardonyx (sardonychès) was recognized by a white part laid on the sard as the nail on the flesh, and that it was also prized because, almost alone among engraved stones, it did not carry off the wax. He credits Scipio Africanus the Elder, on the authority of the historian Demostratus, with being the first to wear a sardonyx among the Romans.

    Pliny the Elder, Natural History, XXXVII, 23 (Littré translation)
  2. Rome, 1st century

    Pliny tells how Polycrates of Samos, frightened by the excess of his good fortune, threw his ring into the deep sea to pay his tribute to Fortune. A fish swallowed it and gave it back in the prince’s kitchen. It seems, writes Pliny, that the stone was a sardonyx, and one is shown in Rome, in the temple of Concord.

    Pliny the Elder, Natural History, XXXVII, 2 (Littré translation)
  3. Bible and Christian tradition

    Kunz cites Flavius Josephus, for whom the sardonyxes of the high priest’s shoulder piece stand for the sun and the moon, and Rabanus Maurus, Archbishop of Mainz in the 9th century, who reads in the sardonyx of the Apocalypse the humility of the saints despite their merits. He holds sardonyx to be the onyx of Exodus.

    G. F. Kunz (1913), chapter on birthstones (Josephus, Rabanus Maurus)

A gestureWear it as a signet, ring, or pendant engraved with your initials, as a reminder of loyalty close at hand.

No stone has a proven effect on health: if you have a health concern, see a health professional.

Its profile

Type
Chalcedony banded in reddish brown (sard) and white (microcrystalline quartz)
Family
Mineral
Composition
SiO2
Mohs hardness
6.5–7 out of 10
Colors
red, brown, white
Common treatments
often dyed or heated
Common imitations
dyed agate ; verre

Caring for it without damaging it

  • WaterYesA quick rinse in warm soapy water, then drying, does not damage it.
  • SaltYesMohs hardness 6.5–7: harder than salt (2.5), it can handle brief contact; rinse afterward.
  • SunYesNo known fading in daylight.
  • HeatAvoidA sudden change in temperature can crack it: no direct heat source.
  • Scratches and knocksResistantMohs hardness 6.5–7: it resists everyday scratches, but not sharp knocks.

Cleansing and charging without damage
Cleansing a crystal: the reported methods
Charging a crystal: moon, flower of life

Nuances and sources

The 1912 list writes “sardonyx” for August, with peridot as the substitute: sard, sardonyx, and onyx are muddled among ancient authors. Kunz says Polycrates’ ring was set with an emerald, where Pliny thinks of a sardonyx. Many stones sold are dyed or heated, and dyed agate imitates sardonyx.

Sardonyx: your questions

Sardonyx, sard, and onyx: what is the difference?

They are three names for banded chalcedony that usage has mixed together. Pliny defines sardonyx as a red sard bearing a white part; onyx is classically banded in black and white. The 1912 list writes “sardonyx” for August, a sign that the two words then designated the same stone. When buying, ask for the exact designation.

Is a dyed sardonyx fake?

Not necessarily: agate is often dyed or heated to sharpen its bands, including the kind sold as sardonyx, which the site points out. It remains chalcedony, but the color is not natural. An overly vivid red and overly regular bands should raise suspicion: ask whether the stone is natural, dyed, or heated.

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