Short answer: August has three birthstones: peridot, spinel and sardonyx. Peridot is a yellowish green gem variety of olivine, found in lava flows and even in meteorites. Spinel is a hard gem in many colors, famous for red stones once mistaken for ruby. Sardonyx, the oldest of the three, is banded red-brown and white chalcedony long used for cameos and seals.
Why does August have three birthstones?
The 1912 list adopted in the United States gave August sardonyx and peridot. In 2016 spinel was added as an additional August birthstone. Today peridot is the most popular choice.
Peridot
What is peridot?
Peridot is the gem variety of olivine, a mineral common deep in the Earth's mantle. Its color runs from yellowish green to greenish yellow, and the most prized is a pure grass green with no hint of yellow or brown. The word comes from the Arabic faridat, "gem". It rates 6.5 to 7 on the Mohs scale.
A gem often mistaken for others
For centuries peridot was confused with topaz and emerald. The Red Sea island once called Topazios, a possible source of the word topaz, actually produced peridot. The Shrine of the Three Holy Kings in Cologne Cathedral is decorated with about 200 carats of gems long believed to be emeralds that are in fact peridot. Peridot appeared in priests' jewelry as early as the second century BCE and later in the chalices and churches of medieval Europe.
Where does peridot come from?
The Egyptian island of Zabargad, the modern name for Topazios, is the oldest recorded source, with mining that may have begun around 340 to 279 BCE. Fine peridot also comes from near Mogok in Myanmar. In the United States, the main source is Arizona: lava flows on what is today the San Carlos Apache Indian Reservation brought peridot to the surface, and some Apache families have worked the mines for decades. Most peridot in jewelry today comes from China, Myanmar, Pakistan, Tanzania, Vietnam and the United States.
Peridot has also reached Earth from space. Pallasite meteorites, made of nickel-iron and olivine, sometimes contain transparent gem-quality peridot.
What is peridot traditionally associated with?
Peridot has been used for centuries as a protective talisman, believed to shield its owner from evil spirits and "terrors of the night". It is the gem of the sixteenth wedding anniversary.
Spinel
What is spinel?
Spinel is a hard gem, 8 on the Mohs scale, in a wide range of colors: intense red, vibrant pink, orange, purple, violet, blue and bluish green. The name comes from the Latin spina, "thorn", after the pointed shape of its crystals.
The "rubies" that were spinel
For centuries red spinel was mistaken for ruby, and some of history's most famous rubies are spinel. The Black Prince's Ruby, about 170 carats, passed through Moorish and Spanish kings before Edward, Prince of Wales, the Black Prince, received it in 1367. It is now set in Britain's Imperial State Crown above the Cullinan II diamond. Spinel was not clearly separated from ruby by its chemistry until the 18th century.
Where does spinel come from?
Major sources include Tajikistan, Myanmar, Sri Lanka, Vietnam, Tanzania and Pakistan. Myanmar's Mogok Stone Tract is famous for hot pink and red spinel; Sri Lanka's Ratnapura district produces blue, pink and purple; Vietnam's Luc Yen region has produced red, purple, pink and violet spinel since the 1980s and vivid blue since the 2000s; and Tanzania yielded pinkish and orangy red spinel in a 2007 discovery.
What is spinel traditionally associated with?
Red gems, spinel among them, were believed to ease anger and promote harmony. Spinel is the gem of the twenty-second wedding anniversary.
Sardonyx
What is sardonyx?
Sardonyx combines two kinds of chalcedony, the microcrystalline form of quartz: sard and onyx. Bands of brownish red to orange sard alternate with white or black layers of onyx. It rates 6.5 to 7 on the Mohs scale. It is the most ancient of the August birthstones.
A stone for seals and cameos
In ancient Rome, sardonyx was popular for seals and signet rings, because hot wax does not stick to it. Its contrasting bands have made it a favorite carving material for cameos and intaglios for thousands of years. It is believed to be one of the stones in the High Priest's breastplate described in the Old Testament, and Roman soldiers wore sardonyx rings carved with Mars for protection in battle. Today it is associated with courage, happiness and clear communication.
The carnelian guide covers sard and carnelian, the red layers of sardonyx, in more detail.
Where does sardonyx come from?
India is notable for sardonyx with strong contrast between its layers. It is also found in Brazil, Germany, the former Czechoslovakia, Madagascar, Uruguay and the United States.
These meanings are traditions and beliefs, not properties of the stones.
Which August birthstone should you choose?
| Peridot | Spinel | Sardonyx | |
|---|---|---|---|
| Mineral | Olivine | Spinel | Chalcedony (quartz) |
| Hardness (Mohs) | 6.5 to 7 | 8 | 6.5 to 7 |
| Look | Transparent yellow-green | Transparent, many colors | Opaque, banded |
| Best for | Pendants, earrings | Rings and everyday wear | Cameos, signets, pendants |
How do you care for August birthstones?
- Peridot: softer than many gems and not recommended for a ring worn every day. Some acids, and even long exposure to acidic perspiration, can damage it. Never use steam or ultrasonic cleaners, since it is vulnerable to sudden temperature changes. Clean it with a soft brush, mild dish soap and warm water, and store it apart from harder gems.
- Spinel: durable enough for rings. Warm, soapy water is always safe; ultrasonic and steam cleaners can be used if the stone has no fractures. High heat can fade some colors.
- Sardonyx: clean it with warm, soapy water and a soft brush, and use ultrasonic and steam cleaners with caution. Like other chalcedony, sardonyx is commonly dyed, and high heat during jewelry repair can affect dyed color.
Browse crystals and minerals at Digital Towns Market
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Peridot, spinel and sardonyx in stock
Frequently asked questions
What is the August birthstone color?
Peridot is yellowish green, the classic August color. Spinel comes in red, pink, orange, purple, violet and blue, and sardonyx is banded red-brown and white.
Can peridot come from meteorites?
Yes. Pallasite meteorites, made of nickel-iron and olivine, sometimes contain gem-quality peridot, though only a few have produced it.
Is spinel the same as ruby?
No. They are different minerals, but red spinel looks so much like ruby that famous "rubies", including the Black Prince's Ruby in the British crown, are spinel. Spinel was separated from ruby by its chemistry in the 18th century.
When was spinel added as an August birthstone?
In 2016, as an additional birthstone alongside peridot and sardonyx.
Which August birthstone is most durable?
Spinel. At 8 on the Mohs scale it is harder than peridot and sardonyx and suits rings worn every day.
Sources
- GIA, August Birthstones: https://www.gia.edu/birthstones/august-birthstones
- Wikipedia, Birthstone: https://en.wikipedia.org/wiki/Birthstone
- Wikipedia, Spinel: https://en.wikipedia.org/wiki/Spinel
- Wikipedia, Onyx (including sardonyx): https://en.wikipedia.org/wiki/Onyx
- GIA, Peridot: https://www.gia.edu/peridot