August Birthstone
Peridot
Also: Spinel · Sardonyx
"Protection, positive energy, and renewal"
About Peridot
Chemical Formula
(Mg,Fe)₂SiO₄ (olivine)
Crystal System
Orthorhombic
Hardness
6.5–7 on Mohs scale
Color
Yellow-Green to Olive Green
Primary Origins
Egypt (Zabargad Island), Pakistan, Myanmar, USA (Arizona), China
Peridot is the one gemstone that glows in the dark — or rather, it glows with a warm yellowish-green light that ancient Egyptians believed was the trapped radiance of the sun. They mined it exclusively on the island of Zabargad in the Red Sea, a volcanic island that was a guarded state secret for centuries, and they gave the stones to their pharaohs as symbols of divine power and solar protection. August's primary birthstone is also one of the most unusual stones in the gemstone world from a geological standpoint: while most gems form in Earth's crust, peridot forms in the mantle — the layer below the crust that sits above the outer core. It is brought to the surface by volcanic eruptions, which is why it is commonly found in volcanic rocks, why Hawaiian beaches contain tiny grains of it, and why the ancient story of peridot as the tears of Pele (the Hawaiian volcano goddess) has a literal geological truth embedded in the mythology. More extraordinary still: peridot has been found in meteorites. The pallasite class of iron-nickel meteorites — some of the most visually striking meteorites in existence — contains olivine crystals (the mineral of which peridot is the gem quality version) that formed in the cores of planetesimals, small planetary bodies that broke apart in the early solar system. The peridot in some pallasites is billions of years old and formed not on Earth but in space. August has two additional birthstones — spinel (added to the official list in 2016) and sardonyx — making it a month of options. But peridot, with its volcanic origin, its extraterrestrial connections, and its five-thousand-year history as the sun's gemstone, is the one that tells the most interesting story.
History
Peridot is one of the oldest gemstones in human history, with mining on the Egyptian island of Zabargad (also called St. John's Island or Topazios) dating back to at least 1500 BCE. Ancient Egyptians called it the gem of the sun and mined it exclusively for their pharaohs — a peridot mine on Zabargad was a state secret [Kunz, G.F., 1913. The Curious Lore of Precious Stones]. Many of Cleopatra's famous emeralds may actually have been peridot — ancient sources frequently confused the two green stones. Peridot was used extensively in medieval European church treasury: gems in the reliquary of the Three Kings in Cologne Cathedral, previously labeled emeralds, were recently identified as peridot.
Mythology & Cultural Traditions
The ancient Egyptians believed peridot was the tears of the sun god Ra — which explains its connection to protection against darkness. Hawaiian tradition holds that peridot is the tears of the volcano goddess Pele, and indeed peridot is commonly found in volcanic basalt formations in Hawaii, where it washes up on some beaches. Meteoritic peridot — found in iron-nickel meteorites called pallasites — was used by prehistoric humans in Greenland to make tools, giving this particular variety a literally extraterrestrial origin.
Geology & Formation
Peridot is the gem quality variety of olivine — one of the most common minerals in Earth's upper mantle. Unlike most gemstones which form in the crust, peridot forms deep in the mantle and is brought to the surface by volcanic activity. The color — ranging from yellow-green to olive to deep green — comes from iron content. Higher iron levels produce deeper green. Notably, peridot has also been found in meteorites (pallasites) and even in Martian soil samples — making it one of the few gems with confirmed extraterrestrial occurrence. [Source: GIA Gem Encyclopedia, gia.edu; Mindat.org]
Famous Peridots
The Shrine of the Three Kings (Cologne Cathedral)
Large peridot stones previously believed to be emeralds are embedded in the reliquary of the Three Kings (c.1180 CE) at Cologne Cathedral in Germany.
The Smithsonian's Pakistani Peridot
A 311.8-carat peridot from Pakistan's Kohistan district is among the largest faceted peridots on display, housed at the Smithsonian's National Museum of Natural History.
Did You Know?
Peridot is one of only two gemstones (diamond is the other) that forms not in the crust but in Earth's mantle, typically 40–50 miles below the surface.
Peridot has been found in meteorites — the pallasite class of iron-nickel meteorites contains olivine crystals that are gem quality in some specimens.
In Hawaii, small peridot crystals wash up naturally on certain beaches, particularly on the Big Island's Mahana Beach (sometimes called Green Sand Beach).
Care Instructions
Clean with warm soapy water and a soft brush only — avoid ultrasonic cleaners (peridot can be sensitive to stress). Protect from acids and harsh chemicals, which attack the stone's surface. Avoid dramatic temperature changes. Peridot is relatively soft (6.5–7) and should be stored carefully to prevent scratching. [GIA, gia.edu]
Frequently Asked Questions
What is the birthstone for August?
The primary birthstone for August is Peridot, with alternates including Spinel and Sardonyx.
What color is Peridot?
Peridot is Yellow-Green to Olive Green. Its chemical formula is (Mg,Fe)₂SiO₄ (olivine).
What does Peridot symbolize?
Peridot symbolizes Protection, positive energy, and renewal.
How hard is Peridot?
Peridot rates 6.5–7 on Mohs scale on the Mohs scale.
Where is Peridot found?
Peridot is primarily found in Egypt (Zabargad Island), Pakistan, Myanmar, USA (Arizona), China.
How should I care for Peridot jewelry?
Clean with warm soapy water and a soft brush only — avoid ultrasonic cleaners (peridot can be sensitive to stress). Protect from acids and harsh chemicals, which attack the stone's surface. Avoid dramatic temperature changes. Peridot is relatively soft (6.5–7) and should be stored carefully to prevent scratching. [GIA, gia.edu]
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