Peridot, spinel, and sardonyx represent the birthstones for August, though peridot is most frequently recognized as the primary gem for those born in this month. This vibrant gemstone, ranging in color from yellowish-green to olive, boasts a history steeped in lore and a geological origin as unique as its hue. Found in volcanic lava and even meteorites, peridot has captivated civilizations for millennia, often mistaken for other, more highly prized gems like emeralds and topaz. This article will delve into the history, geological formation, gemological properties, symbolism, and care of peridot, offering a comprehensive overview of this fascinating August birthstone.
History and Lore
Peridot’s history stretches back thousands of years. Ancient Egyptians revered peridot, referring to it as the “gem of the sun.” Some historians speculate that Cleopatra’s famed emerald collection actually consisted largely of peridot sourced from the Red Sea island of Zabargad. This island, meaning “olivine” in Arabic, was a significant source of the gem for centuries, despite its harsh and desolate environment.
The gem was also mined on Topazios (now St. John’s Island) in the Red Sea, leading to a historical confusion with topaz, as the island’s name became associated with the gem. Throughout history, peridot has been confused with other green gemstones, including emeralds. Notably, gems believed to be emeralds adorning the Shrine of the Three Holy Kings in Germany’s Cologne Cathedral are, in fact, peridot.
Beyond Egypt, peridot has been found in archaeological sites across the globe, indicating its widespread use in ancient jewelry and ornamentation. Its enduring appeal stems not only from its beauty but also from the beliefs surrounding its protective and healing properties.
Geological Formation and Sources
Peridot is a gem-quality variety of olivine, a mineral composed of magnesium-iron silicates. Its distinctive green color arises from the presence of iron within the crystal structure, with varying iron content influencing the shade, ranging from olive to lime green, and sometimes exhibiting a brownish tinge.
The formation of peridot is often linked to extreme geological conditions. It is brought to the Earth’s surface from the upper mantle through volcanic activity, specifically within hardened lava flows. Uniquely, peridot has also been discovered within Pallasite meteorites, offering a cosmic origin for this terrestrial gem. While meteorite-sourced peridot is often too small for jewelry, it adds to the stone’s mystique.
Currently, significant sources of peridot include Norway, Brazil, China, Kenya, Sri Lanka, Australia, Mexico, and the Mogok district of Myanmar (Burma). The San Carlos Indian Reservation in Arizona is also known for producing smaller peridot crystals. The Red Sea region, particularly Zabargad, remains a historically important, though less commercially significant, source.
Gemological Properties
Peridot’s chemical formula is (Mg,Fe)2SiO4, indicating its composition of magnesium, iron, and silicon dioxide. It typically exhibits a vitreous luster, giving it a glass-like sheen. The gem’s color is consistently green, even under varying lighting conditions, though finer stones appear greener under artificial light, earning them the nickname “evening emeralds.”
Here's a summary of peridot's key gemological properties:
| Property | Value |
|---|---|
| Chemical Formula | (Mg,Fe)2SiO4 |
| Color | Yellowish-green to Olive Green |
| Luster | Vitreous |
| Hardness (Mohs) | 6.5 - 7 |
| Crystal System | Orthorhombic |
| Specific Gravity | 3.34 - 3.48 |
| Refractive Index | 1.654 - 1.683 |
Peridot possesses a hardness of 6.5 to 7 on the Mohs scale, making it relatively durable but susceptible to scratching from harder materials. Its specific gravity ranges from 3.34 to 3.48, and its refractive index falls between 1.654 and 1.683. These properties contribute to its brilliance and distinct appearance.
Symbolism and Metaphysical Beliefs
Throughout history, peridot has been associated with various symbolic meanings. It is often believed to symbolize abundance, protection, and positivity. Ancient cultures attributed protective powers to the gem, shielding wearers from nightmares and evil spirits.
In modern times, peridot is thought to promote mental clarity, emotional balance, and overall well-being. Some believe it can attract wealth and prosperity, while others associate it with healing properties, particularly for the liver and digestive system. While these metaphysical beliefs are not scientifically substantiated, they contribute to the gem’s enduring appeal and cultural significance.
Care and Cleaning
Due to its hardness of 6.5 to 7 on the Mohs scale, peridot requires careful handling to prevent scratches. It is advisable to remove peridot jewelry before engaging in strenuous activities or when exposed to harsh chemicals.
Cleaning peridot is relatively straightforward. Warm, soapy water and a soft brush are generally sufficient to remove dirt and grime. Avoid ultrasonic cleaners and steam cleaners, as these can potentially damage the gem. Polishing with a soft cloth will restore its luster. It is also recommended to store peridot jewelry separately from harder gemstones to prevent scratching.
Conclusion
Peridot, the captivating green birthstone of August, offers a unique blend of historical significance, geological intrigue, and aesthetic beauty. From its ancient origins in the Red Sea to its modern-day appeal as a vibrant gemstone, peridot continues to fascinate and inspire. Its association with abundance, protection, and positivity, coupled with its relatively accessible price point, makes it a popular choice for jewelry enthusiasts and a meaningful gift for those born in the eighth month of the year. The gem’s formation in volcanic lava and even meteorites adds to its mystique, solidifying its place as a truly remarkable and enduring gemstone.