For those born in August, the choice of a birthstone is uniquely abundant. The month is officially represented by three distinct gems: peridot, spinel, and sardonyx. Among these, peridot stands out as the primary modern birthstone, celebrated for its distinctive lime-green glow and a history that stretches back millennia. This gemstone, formed under some of the most extreme conditions on Earth and even in space, carries a legacy of being mistaken for emeralds, revered as a "gem of the sun," and believed to bring strength and good fortune to its wearer. While spinel offers a spectrum of colors and sardonyx provides ancient grounding, peridot's consistent and vibrant green has secured its place as the most recognized August gem. This article delves into the geological formation, rich history, gemological properties, and enduring symbolism of peridot, providing a comprehensive guide for enthusiasts, collectors, and anyone captivated by this gem of sunlight.
History and Lore
Peridot’s history is as vibrant as its color, with evidence of its use dating back to ancient civilizations. The gemstone was treasured by ancient cultures for its beauty and was believed to possess powerful protective and healing properties. In ancient Egypt, peridot was referred to as the "gem of the sun," and it was thought to ward off nightmares while bringing happiness and strength to its wearer. The Egyptians associated peridot with the sun god and believed it to be a divine gift, using it in the construction of religious and royal artifacts.
The name "peridot" is believed to derive from the Arabic word faridat, meaning "gem." Throughout history, peridot has often been confused with other green gemstones, including emerald and topaz. A significant historical example involves the Red Sea island of Topazios, which was a purported source of the name "topaz," but actually produced peridot. This confusion extended to medieval Europe, where many "emeralds" in cathedral treasures, such as the 200-carat gems adorning the Shrine of the Three Holy Kings in Germany’s Cologne Cathedral, were later identified as peridots. Some historians even speculate that Cleopatra’s famous emerald collection may have been comprised of peridot.
The journey of peridot as an official birthstone is more recent. For centuries, sardonyx was considered the traditional August birthstone, with a history dating back over 4,000 years. In 1912, the National Association of Jewelers (now Jewelers of America) established a modern list of birthstones, officially naming peridot as the birthstone for August. This decision was made to provide more options for color, affordability, and availability. Spinel was added as a third official birthstone for August much later, in 2016, by the American Gem Trade Association (AGTA), further diversifying the choices for those born in the month.
Geological Formation and Sources
Peridot, the gem-quality variety of the mineral olivine, is unique in its formation. It is one of the few gemstones that occurs in only one color family—green—though its shade can vary significantly from yellowish-green to olive to brownish-green, depending on the iron content. Unlike many gemstones that form in the Earth's crust, peridot is born from the intense heat and pressure of the Earth's mantle. It is brought to the surface by volcanic activity, often found in hardened lava that carries it from deep within the Earth.
What makes peridot truly extraordinary is its extraterrestrial origin. It is also found in meteorites that have traveled from outer space, making it one of the few gems that can be found on both Earth and in space. This dual origin underscores the gemstone's formation under extreme conditions, a characteristic that adds to its allure and mystique.
While peridot deposits are found in various parts of the world, including Arizona, Myanmar, Pakistan, and China, the most famous historical source is the island of Zabargad in the Red Sea. This island, known in antiquity as Topazios, was the primary source of peridot for the ancient world. The gemstones mined there were used in ancient Egyptian jewelry and artifacts, contributing to its reputation as the "gem of the sun."
Gemological Properties
Peridot is a gemstone with distinct and well-defined physical and chemical properties. As a variety of the mineral olivine, its chemical formula is (Mg, Fe)₂SiO₄, a magnesium iron silicate. The color of peridot is primarily determined by its iron content, with higher iron concentrations leading to deeper olive greens and lower concentrations resulting in lighter, yellowish-green hues.
In terms of hardness, peridot ranks between 6.5 and 7 on the Mohs scale, making it a relatively durable gemstone suitable for various types of jewelry. However, its hardness is accompanied by a lack of cleavage, which means it does not have natural planes of weakness that can cause it to split. This property, combined with its good toughness, makes peridot a resilient choice for everyday wear, though it should still be protected from sharp blows and extreme temperature changes to avoid damage.
Peridot's refractive index ranges from 1.65 to 1.69, and it is doubly refractive, a characteristic that can be observed under magnification. The gemstone's specific gravity typically falls between 3.27 and 4.37, and it is transparent to translucent, with the finest specimens being eye-clean and displaying a vibrant, even color.
The following table summarizes key gemological properties of peridot based on the provided sources:
| Property | Description |
|---|---|
| Mineral Family | Olivine |
| Chemical Formula | (Mg, Fe)₂SiO₄ |
| Color | Yellowish-green to olive to brownish-green |
| Hardness (Mohs Scale) | 6.5 - 7 |
| Refractive Index | 1.65 - 1.69 |
| Specific Gravity | 3.27 - 4.37 |
| Transparency | Transparent to translucent |
| Origin | Earth's mantle (volcanic), meteorites (extraterrestrial) |
Symbolism and Metaphysical Beliefs
Peridot has been imbued with symbolic meaning and metaphysical beliefs across various cultures and eras. Its association with the sun in ancient Egypt led to its reputation as a stone of light, positivity, and vitality. It was believed to protect against nightmares and bring happiness and strength to the wearer.
In modern crystal healing and metaphysical traditions, peridot is often linked to the heart chakra, symbolizing healing, joy, and the release of negative patterns. It is considered a bright, uplifting stone that can boost mood and confidence, and it is associated with prosperity, good fortune, and peace. For those born in August, peridot is believed to bring luck, success, and a sense of inner light, serving as a reminder of one's strength and connection to timeless energy.
While these beliefs are part of the gemstone's cultural lore and are widely held by enthusiasts, it is important to note that they fall outside the realm of scientific gemology and are not universally accepted as factual properties of the stone.
Care and Cleaning
Given its gemological properties, peridot requires careful maintenance to preserve its beauty and integrity. With a hardness of 6.5 to 7 on the Mohs scale, it is durable enough for most jewelry but can be scratched by harder materials like diamonds, sapphires, and rubies. It is also susceptible to thermal shock, so it should not be subjected to sudden temperature changes, such as moving from a hot environment to a cold one or vice versa.
For cleaning, peridot can be safely washed with warm, soapy water and a soft brush. It is advisable to avoid harsh chemicals, ultrasonic cleaners, and steam cleaning, as these can potentially damage the stone or its settings. When storing peridot jewelry, it should be kept separately from other gems and jewelry to prevent scratches. With proper care, peridot jewelry can maintain its vibrant green glow for generations.
Conclusion
Peridot stands as a remarkable gemstone, both in its geological origins and its historical significance. As the primary modern birthstone for August, it offers a unique combination of durability, vibrant color, and a rich legacy. From its formation in the Earth's mantle and its extraterrestrial presence in meteorites to its ancient reputation as the "gem of the sun," peridot continues to captivate gemstone enthusiasts and jewelry buyers alike. Its consistent green hue, which has been mistaken for emerald throughout history, and its association with positive attributes like strength, good fortune, and peace make it a meaningful choice for those born in the month of August. Whether selected for its beauty, its symbolism, or its unique story, peridot remains a timeless gem that embodies the warmth and energy of summer.