August is one of only three months in the year to claim three distinct birthstones, offering a remarkable spectrum of color, history, and geological origin. Those born in this summer month can choose from the vibrant green of peridot, the dazzling array of colors in spinel, or the ancient, banded beauty of sardonyx. This unique trio—officially recognized by major trade organizations—provides a gem for every preference, from the modern seeker of natural brilliance to the historian appreciating stones with millennia of lore. The August birthstones are not merely decorative; they represent a fascinating convergence of volcanic creation, mistaken identity in royal treasuries, and ancient symbolism tied to strength and protection. This article provides a detailed exploration of these three gems, examining their geological formation, gemological properties, historical significance, and the metaphysical beliefs that continue to make them sought-after choices for jewelry enthusiasts and collectors alike.
History and Lore: A Journey Through Time
The history of August’s birthstones is a tale of evolution, beginning with the ancient sardonyx and expanding to include the luminous peridot and the rediscovered brilliance of spinel.
Sardonyx: The Ancient Foundation Sardonyx holds the distinction of being the original and traditional August birthstone, with a lineage stretching back over 4,000 years. It is a variety of onyx, specifically composed of alternating layers of sard (a reddish-brown chalcedony) and onyx (a white or black chalcedony), creating its characteristic banded appearance. Its significance is deeply rooted in antiquity; historical accounts confirm that sardonyx was one of the gems found in the foundation of New Jerusalem and was prominently featured on the High Priest’s breastplate, as described in biblical texts. Ancient civilizations, including the Romans and Greeks, prized sardonyx for its durability and striking contrast, frequently carving it into cameos and intaglios for signet rings. The stone was believed to grant the wearer strength, courage, and protection, particularly in battle, and was associated with stable, harmonious relationships.
Peridot: The "Gem of the Sun" Peridot, the primary modern August birthstone, has a history often clouded by mistaken identity. Known historically as the "gem of the sun" by the ancient Egyptians, peridot was cherished for its glowing green hue, which was said to ward off nightmares and evil spirits. The name "peridot" is derived from the Arabic word faridat, meaning gem. A significant chapter in peridot’s history involves the Red Sea island of Topazios, a source that produced peridot but lent its name to the gemstone topaz, leading to centuries of confusion. Perhaps the most famous historical misidentification occurred in Germany’s Cologne Cathedral, where the Shrine of the Three Holy Kings is adorned with 200 carats of gems long believed to be emeralds; modern analysis revealed them to be peridot. Some historians even speculate that Cleopatra’s legendary collection of emeralds may have, in fact, been peridot. Peridot was officially added to the modern birthstone list in 1912.
Spinel: The Great Impostor Spinel is the newest addition to the August birthstone family, officially recognized by the American Gem Trade Association (AGTA) and Jewelers of America (JA) in 2016. For centuries, spinel was underappreciated, largely because it was frequently mistaken for ruby. Some of the world’s most famous "rubies," such as the Black Prince’s Ruby and the Timur Ruby in the British Crown Jewels, are, in reality, magnificent red spinels. This history of being a "great impostor" has led to a modern resurgence of interest, as consumers seek out vibrant, durable, and often more affordable alternatives to ruby. Its recent inclusion acknowledges its beauty and distinct identity, offering August-born individuals a third, brilliant option.
Geological Formation and Global Sources
The three August birthstones originate from vastly different geological environments, from deep within the Earth’s mantle to volcanic flows and even outer space.
Peridot: From the Mantle and Beyond Peridot is unique among gemstones as it is formed under extreme conditions deep within the Earth’s mantle. Unlike many gems that crystallize in the crust, peridot is brought to the surface by volcanic activity. It is commonly found in mafic and ultramafic igneous rocks. Notably, some of the finest peridot crystals have been discovered in pallasite meteorites, offering proof of its formation in outer space as well. Commercial sources of peridot are primarily located in Arizona, Pakistan, and China, with Arizona’s San Carlos Apache Reservation being a particularly significant producer. The stone’s natural brightness does not typically require enhancements, making it a favorite among lovers of natural gemstones.
Spinel: A Magnesium Aluminum Oxide Spinel forms under similar geological conditions to ruby and sapphire but in magnesium-rich environments. It is found in metamorphic rocks and alluvial deposits. Historically, the most famous source of red spinel was the Badakhshan region of Central Asia (modern-day Afghanistan and Tajikistan). Today, significant sources include Vietnam, which produces vibrant red and pink spinels, and Sri Lanka, known for a wide variety of colors. Tanzania also yields notable spinel, particularly in the reddish-orange and pink hues.
Sardonyx: A Variety of Chalcedony Sardonyx is a banded variety of chalcedony, which is a cryptocrystalline form of quartz (silicon dioxide). Its formation occurs in volcanic rocks and geodes. The distinct banding is the result of successive layers of sard and onyx being deposited over time. Major sources for sardonyx include India, Brazil, Germany, and the United States. While not as commercially prominent as peridot or spinel, it remains accessible and is often carved into cameos, intaglios, and beads.
Gemological Properties
The gemological properties of the August birthstones differ significantly, offering distinct characteristics for jewelers and collectors.
| Property | Peridot | Spinel | Sardonyx |
|---|---|---|---|
| Chemical Composition | (Mg,Fe)₂SiO₄ (Olivine) | MgAl₂O₄ (Magnesium Aluminum Oxide) | SiO₂ (Silicon Dioxide - Chalcedony) |
| Hardness (Mohs Scale) | 6.5 - 7 | 8 | 6.5 - 7 |
| Crystal System | Orthorhombic | Cubic | Trigonal (Cryptocrystalline) |
| Refractive Index | 1.65 - 1.69 | 1.718 | 1.53 - 1.54 |
| Typical Colors | Yellow-green to olive green | Red, pink, orange, blue, black | Bands of reddish-brown (sard) and white/black (onyx) |
Peridot is a member of the olivine mineral group. Its color ranges from yellow-green to deep olive, with the most valued stones displaying a rich, lime-green hue. With a hardness of 6.5 to 7 on the Mohs scale, it is moderately durable but can be susceptible to chipping if struck with force due to its poor cleavage. It is one of the few gemstones that occurs in only one color family.
Spinel boasts an impressive hardness of 8 on the Mohs scale, making it exceptionally durable and suitable for all types of jewelry, including rings and bracelets. It has a high refractive index, contributing to its brilliance, and is available in a stunning variety of colors. While red is the most popular and valuable, spinel also occurs naturally in vibrant blues, pinks, oranges, and even black.
Sardonyx, like other varieties of chalcedony, has a hardness of 6.5 to 7 and a lower refractive index than peridot or spinel, giving it a more waxy luster. Its defining feature is its banding, which can be straight or curved. It is often cut en cabochon to highlight these bands or carved into intricate designs.
Symbolism and Metaphysical Beliefs
Beyond their physical beauty, the August birthstones are rich in symbolism and are believed to possess various metaphysical properties.
- Peridot is often associated with positivity, joy, abundance, and confidence. Ancient cultures believed it could ward off evil and protect the wearer. In modern crystal healing, it is considered a "Heart Chakra" crystal, used to support emotional healing, open the heart to love, and release negative patterns. Its bright energy is said to be uplifting and mood-boosting.
- Spinel is viewed as a stone of renewal, inspiration, and vitality. It is believed to help restore energy, inspire hope, and provide encouragement during difficult times. Different colors of spinel are associated with different chakras, but the stone as a whole is considered a high-energy gem for grounding and revitalizing one’s spirit.
- Sardonyx is deeply connected to the earth and is considered a powerful grounding and protective stone. It is traditionally associated with strength, courage, and steadfastness. Metaphysical beliefs suggest that sardonyx can promote stable relationships, offer protection from negative energy, and enhance willpower and discipline. Its ancient roots contribute to its reputation as a stone of history and legacy.
Care and Cleaning
Proper care ensures the longevity and beauty of these gemstones. Due to their differing hardness and durability, specific cleaning methods are recommended.
Peridot requires careful handling because of its moderate hardness (6.5-7) and lack of cleavage. It is sensitive to rapid temperature changes and harsh chemicals. To clean peridot jewelry, use warm, soapy water and a soft brush. Avoid ultrasonic cleaners and steam cleaning, as the heat and vibrations can damage the stone.
Spinel is one of the more durable gemstones, with a hardness of 8 and good toughness. It can be safely cleaned in an ultrasonic cleaner and with warm soapy water. However, it is always wise to inspect older spinel jewelry for any fractures before using an ultrasonic device. Steam cleaning is generally safe, but caution is advised if the stone has inclusions.
Sardonyx, being a variety of chalcedony, is relatively durable but can be scratched by harder materials. It is safe to clean with warm, soapy water and a soft cloth. Ultrasonic cleaners are typically safe for untreated sardonyx, but caution is advised if the stone has been dyed or treated, as the process can remove the color enhancement.
Conclusion
The trio of August birthstones—peridot, spinel, and sardonyx—offers an unparalleled choice for those born in the eighth month. From the ancient, protective bands of sardonyx to the solar brilliance of peridot and the rediscovered splendor of spinel, each stone carries a unique narrative of geological formation and human history. Whether selected for its vibrant color, its remarkable durability, or its deep-seated symbolism of strength and renewal, an August birthstone is a meaningful and beautiful connection to the natural world and the rich tapestry of gemological heritage.