August Birthstones: Peridot, Spinel and Sardonyx
August has three official birthstones: peridot, spinel and sardonyx. Every one counts, so you can choose by color, hardness or taste. Each is described below.
Peridot, an August birthstone
| Color | Yellowish green |
|---|---|
| Mineral | Olivine |
| Hardness | 6.5 to 7 on the Mohs scale (diamond is 10) |
| Main sources | China, Myanmar, Pakistan, Tanzania, Vietnam, United States (including Hawaii) |
| Anniversary gem | 16th wedding anniversary |
Is peridot good for everyday wear?
GIA does not recommend peridot for a ring worn every day: at 6.5 to 7 on the Mohs scale it cannot take hard wear. Some acids, and even acidic sweat over a long time, can damage it.
Peridot history
- The 200 carats of "emeralds" on the Shrine of the Three Kings in Cologne Cathedral are in fact peridot.
- The name is thought to come from the Arabic faridat, meaning gem.
How to clean peridot
- Warm, soapy water and a soft brush: always safe.
- Ultrasonic cleaner: not recommended.
- Steam cleaner: not recommended.
Sudden temperature changes can crack it. Use a soft brush, mild dish soap and warm water, and store it where harder gems cannot scratch it.
Spinel, an August birthstone
| Color | Red, pink, blue and other colors |
|---|---|
| Mineral | Spinel |
| Hardness | 8 on the Mohs scale (diamond is 10) |
| Main sources | Myanmar, Sri Lanka, Tajikistan, Vietnam, Tanzania, Pakistan |
| Anniversary gem | 22nd wedding anniversary |
Is spinel good for everyday wear?
Spinel is 8 on the Mohs scale, so GIA calls it a typically durable gem for rings and other jewelry.
Spinel history
- The Black Prince's "Ruby", about 170 carats and owned by a line of Moorish and Spanish kings, is a spinel.
- Spinel was not clearly told apart from ruby until the 18th century.
How to clean spinel
- Warm, soapy water and a soft brush: always safe.
- Ultrasonic cleaner: only for stones without fractures or fillings.
- Steam cleaner: only for stones without fractures or fillings.
Stable in light and chemicals; very high heat can fade the color. Warm, soapy water is always safe.
Sardonyx, an August birthstone
| Color | Bands of brownish red and white |
|---|---|
| Mineral | Chalcedony: layers of sard and onyx |
| Hardness | 6.5 to 7 on the Mohs scale (diamond is 10) |
| Main sources | India, Brazil, Germany, Madagascar, Uruguay, United States |
Is sardonyx good for everyday wear?
At 6.5 to 7 on the Mohs scale, sardonyx needs care when worn, especially as a ring.
Sardonyx history
- Romans used it for seals and signet rings because hot wax does not stick to it.
- Roman soldiers wore sardonyx rings carved with Mars, the god of war.
How to clean sardonyx
- Warm, soapy water and a soft brush: always safe.
- Ultrasonic cleaner: not recommended.
- Steam cleaner: not recommended.
Clean with warm, soapy water. It is often dyed, and high heat can change the color.
August birthstone and birth flower
August also has two birth flowers: the gladiolus and poppy, which stand for strength, remembrance and peace. The Birth Flower Finder covers every month.
Buying for someone not born in August? The Birthstone Finder shows every month's stones and colors in one chart. Peridot and spinel are also given for wedding anniversaries; the Anniversary Calculator shows which one is coming up next. If the gift is a surprise, a birthday countdown counts down to the day.
Birthstones for other months
August Birthstones questions
What is the August birthstone?
August has three birthstones: Peridot, Spinel and Sardonyx. All of them are official, so you can choose the one you like best.
What color is the August birthstone?
Peridot: yellowish green. Spinel: red, pink, blue and other colors. Sardonyx: bands of brownish red and white.
Which August birthstone is the hardest?
Spinel, at 8 on the Mohs scale. Peridot is 6.5 to 7 and sardonyx is 6.5 to 7.
Is sardonyx a kind of quartz?
In a way. Sardonyx is chalcedony, a form of quartz, made of layers of sard and onyx in bands of brownish red and white. March's bloodstone is chalcedony too, while February's amethyst and November's citrine are varieties of quartz itself.
Is peridot an anniversary gem?
Yes. GIA gives peridot for the 16th wedding anniversary.
Why does August have more than one birthstone?
The US list from 1912 has been updated a few times. Spinel was added to August in 2016, by the American Gem Trade Association and Jewelers of America. The American Gem Society also keeps sardonyx, an older August stone.
Published October 7, 2026. Last updated October 7, 2026.