Colors
- Bands of reddish brown, cream, black and white; clean, well defined layers are valued most
Browse other gems by color: Brown · Orange · White and colorless · Black
Where Sardonyx comes from
- India
- Brazil
- Uruguay
- Germany
- Western United States
Sardonyx meaning and history
Greek and Roman warriors wore engraved sardonyx talismans for courage and protection.
It stayed popular for cameos through the Renaissance.
Meanings and powers attributed to gems are history and folklore. We report them; we do not claim a stone can do anything.
How hard is Sardonyx?
Sardonyx is 6.5 to 7 on the Mohs scale, where talc is 1, quartz 7 and diamond 10.
See every birthstone on the hardness chart
How to clean and care for Sardonyx
| Warm soapy water | Warm water, mild soap and a soft cloth or brush |
|---|---|
| Ultrasonic cleaner | Not covered by AGS |
| Steam cleaner | Not covered by AGS |
Heat, light and chemicals: Avoid harsh chemicals and long exposure to heat.
AGS suggests earrings, necklaces or protective settings for everyday wear because it is relatively soft.
Can you wear Sardonyx every day?
Wear with care Can chip, crack or scratch. Protective settings, pendants and earrings are safer than everyday rings. Check other stones.
Compare Sardonyx
Peridot vs Sardonyx · Spinel vs Sardonyx
Frequently asked questions
What is Sardonyx?
A banded chalcedony quartz with alternating layers of sard and onyx, used for jewelry, seals and cameos.
What month is Sardonyx the birthstone for?
August. It shares the month with Peridot and Spinel.
How hard is Sardonyx?
6.5 to 7 on the Mohs scale.
How do you clean Sardonyx?
Warm soapy water: warm water, mild soap and a soft cloth or brush. Ultrasonic cleaner: not covered by AGS. Steam: not covered by AGS.
What does Sardonyx symbolize?
Greek and Roman warriors wore engraved sardonyx talismans for courage and protection. It stayed popular for cameos through the Renaissance. These are traditions and history, not claims about what the stone can do.
Sources
- AGS: Sardonyx (hardness, toughness, stability, cleaning, treatments)
- AGS: Sardonyx (what it is, colors, sources, history)
- American Gem Society: Birthstones (birthstone months)
Checked October 16, 2026.