For those born in the eighth month of the year, the choice of a birthstone is not a singular one. August is uniquely distinguished in the gemological calendar by offering three official birthstones: peridot, spinel, and sardonyx. This triad provides a spectrum of color, history, and symbolism, reflecting the vibrant energy of summer. Each stone carries its own distinct narrative, from ancient amulets to modern marvels, offering August-born individuals a rich variety of options that connect them to a legacy of beauty and strength.
The inclusion of multiple stones for August is a result of an evolving tradition, balancing historical precedence with the practicalities of modern gemology. Sardonyx stands as the original, ancient stone, with a history stretching back millennia. Peridot, with its captivating lime-green hue, became the official birthstone in the early 20th century. Most recently, spinel was added to the list, acknowledging its own significant history and stunning beauty, which was often mistaken for other gems. Together, these three stones—peridot, spinel, and sardonyx—offer a comprehensive palette that captures the warmth and brilliance of their birth month.
The Historical Journey of August's Gems
The history of August's birthstones is as varied and colorful as the stones themselves, spanning ancient civilizations, royal courts, and religious artifacts. Each gem has a unique story that contributes to its modern status.
Sardonyx: The Ancient Protector
Sardonyx is the oldest of the three, with a documented history that dates back more than 4,000 years. Highly valued in ancient Egypt, Greece, and Rome, this banded variety of chalcedony was primarily used to create seals, amulets, and cameos. Its alternating layers of sard (a reddish-brown chalcedony) and onyx (a black and white banded chalcedony) created a visually striking effect. The ancients believed that the stone’s bands symbolized strength, protection, and clarity of thought. Roman soldiers would often wear sardonyx rings, believing the stone would grant them courage and protect them from harm in battle. Its use in signet rings was also practical; the hard surface was ideal for pressing into hot wax to create a seal, a practice that continued for centuries.
Peridot: The Gem of the Sun
Peridot, the most well-known of the modern August stones, has a history that is equally storied. Known as the "gem of the sun" by the ancient Egyptians, they believed it brought health, happiness, and protection from nightmares. This vibrant green gem was mined on the Red Sea island of Topazios, a location that ironically contributed to centuries of confusion with topaz. Peridot was often mistaken for other precious green stones throughout history. The 200 carats of gems decorating the Shrine of the Three Holy Kings in Germany’s Cologne Cathedral were believed to be emeralds for centuries but are now known to be peridot. Some historians even speculate that Cleopatra’s famous emerald collection may have actually been comprised of peridot. The word “peridot” itself is derived from the Arabic faridat, meaning "gem."
Spinel: The Great Impostor
Spinel’s journey to becoming an official August birthstone is a story of rediscovery. For centuries, red spinel was mistaken for ruby, earning it the title "the great impostor" in the gem world. Some of the world's most famous "rubies" are, in fact, spinels. The Black Prince's Ruby, a massive 170-carat red gem that sits in the British Imperial State Crown, is a notable example of a red spinel. Similarly, the Timur Ruby, a 361-carat gem, is also a spinel. These stones were prized by royalty and conquerors alike, often passing through the hands of figures like Timur and entering the British Crown Jewels. It was not until the development of modern gemology that spinel was recognized as a distinct mineral species with its own unique properties. Its inclusion as an official birthstone in 2016 by the American Gem Trade Association (AGTA) was a long-overdue acknowledgment of its own beauty and historical significance.
The evolution of the August birthstone list reflects a broader trend in the jewelry industry. The original list of birthstones was formalized in 1912 by the National Association of Jewelers (now Jewelers of America), which designated peridot as the official August stone. Sardonyx was recognized as the traditional stone. The addition of spinel in 2016 provided consumers with more options for color, affordability, and availability, while also honoring a gem with a rich, albeit often confused, history.
Geological Formation and Sources
The origins of these three gems are as diverse as their appearance, formed under vastly different geological conditions and sourced from specific locations around the globe.
Peridot: From the Mantle and Beyond
Peridot is the gem variety of the mineral olivine, a magnesium iron silicate. What makes peridot geologically unique is its formation under extreme conditions. It is one of the few gemstones that can be found in hardened lava that has carried it from deep within the Earth’s mantle to the surface. This process allows for the formation of peridot in volcanic rocks. Even more remarkably, peridot has also been found in meteorites that have traveled from outer space, making it a truly cosmic gem. The primary sources for peridot include Pakistan, Myanmar, and Arizona in the United States. The stone’s signature lime-green glow is a result of its chemical composition, specifically the presence of iron.
Spinel: A Durable Delight
Spinel is a magnesium aluminum oxide, and its formation typically occurs in the metamorphic rocks of marble and alluvial deposits. For centuries, the most prized red spinels came from the historic mines of Badakhshan, a region in modern-day Tajikistan and Afghanistan. These mines were the source of the large red spinels that found their way into royal collections across Asia and Europe. Other significant sources include Sri Lanka and Vietnam, which produce a variety of colors. Spinel’s durability and wide range of hues have made it a favorite among gem collectors and jewelers seeking alternatives to more traditional gemstones.
Sardonyx: The Banded Beauty
As a variety of chalcedony, which is itself a variety of quartz, sardonyx is composed of silicon dioxide. Its distinctive banding is formed when layers of sard and onyx are deposited sequentially. This process occurs in volcanic rock cavities, where silica-rich fluids solidify over time. Major sources for sardonyx include India, Brazil, Germany, and the United States. The quality of sardonyx is judged by the sharpness and contrast of its bands; the most desirable specimens feature clear, distinct lines between the reddish-brown sard and the black or white onyx.
Gemological Properties
Understanding the physical and chemical properties of these gems is essential for appreciating their unique characteristics, durability, and value.
| Gemstone | Mineral Family | Chemical Composition | Hardness (Mohs Scale) | Refractive Index | Typical Colors |
|---|---|---|---|---|---|
| Peridot | Olivine | (Mg, Fe)₂SiO₄ | 6.5 - 7 | 1.65 - 1.69 | Yellowish-green to olive green |
| Spinel | Spinel | MgAl₂O₄ | 8 | 1.71 - 1.73 | Vivid red, pink, orange, blue, black |
| Sardonyx | Chalcedony (Quartz) | SiO₂ | 7 | 1.53 - 1.54 | Banded reddish-brown and black/white |
Peridot Properties
Peridot, with a hardness of 6.5 to 7 on the Mohs scale, is moderately durable but can be susceptible to scratching and chipping if handled roughly. It is a member of the olivine family and its color is determined by its iron content, ranging from bright yellow-green to a deeper olive green. A key characteristic of peridot is its single refractive nature, which means light passes through it in a single direction, resulting in good brilliance and clarity. When evaluating peridot, the most valued stones are those with a rich, intense green color free of strong yellow or brownish tints.
Spinel Properties
Spinel is an exceptionally durable gemstone, rating an 8 on the Mohs scale, making it harder than quartz and suitable for all types of jewelry, including rings and bracelets that are subject to daily wear. Its chemical composition is magnesium aluminum oxide. Spinel is known for its excellent clarity, as it is typically free of inclusions. It exhibits single refractive properties, similar to peridot, which contributes to its brilliance. While red is the most famous and sought-after color, spinel occurs in a breathtaking array of hues, including vibrant pinks, oranges, and the highly prized cobalt blue.
Sardonyx Properties
Sardonyx, with a hardness of 7, is also quite durable and well-suited for jewelry that may encounter some wear. As a variety of chalcedony (microcrystalline quartz), its structure is composed of fine intergrowths of quartz crystals. Its most defining feature is its banding, which is caused by the alternating layers of sard and onyx. The stone is opaque, and its value is often tied to the artistry of the lapidary who cuts it to best display the contrast of its bands. Sardonyx is also used for cameos and intaglios, where the different colored layers can be carved to create a bas-relief image.
Symbolism and Metaphysical Beliefs
Across cultures and through the ages, all three of August's birthstones have been imbued with powerful symbolic meanings and metaphysical properties.
- Sardonyx: The ancient world viewed sardonyx as a stone of strength and protection. Roman soldiers wore it for courage, and it was believed to bring stability and clarity of mind to its wearer. It is often associated with happy marriages and happy homes, making it a popular choice for talismans meant to secure relationships.
- Peridot: As the "gem of the sun," peridot was believed to possess solar energy, bringing warmth, light, and power to its owner. Ancient cultures held that it could ward off evil spirits and protect the wearer from nightmares. It is also associated with healing, renewal, and growth, thought to open the heart to joy and new relationships.
- Spinel: While its long history of being mistaken for ruby and diamond has somewhat obscured its own unique lore, spinel is now celebrated for its own energetic properties. It is often associated with revitalizing energy, inspiring a sense of hope and resilience. Red spinel, in particular, is linked to passion and physical vitality, while other colors are believed to promote mental clarity and calm.
Care and Cleaning
Proper care is crucial for maintaining the beauty and longevity of August's birthstones. Due to their differing hardness levels, each requires slightly different handling.
Caring for Peridot (Hardness 6.5-7)
Because of its moderate hardness, peridot can be scratched by harder gems and daily wear can take a toll. It is best suited for pendants or earrings rather than rings that might experience frequent impact. To clean peridot, use warm, soapy water and a soft brush. Avoid ultrasonic cleaners and steam cleaning, as the stone can be sensitive to sudden temperature changes and vibrations that could cause fractures.
Caring for Spinel (Hardness 8)
Spinel is very durable and easy to care for. Its high hardness makes it resistant to scratching and it can be safely cleaned using warm, soapy water and a soft brush. It is also generally safe to use an ultrasonic cleaner, though it is always wise to check if the stone has any fractures first. Steam cleaning is also typically safe for spinel.
Caring for Sardonyx (Hardness 7)
Sardonyx is durable enough for everyday wear. As a variety of quartz, it is relatively stable, but its banding can sometimes be susceptible to damage from sharp blows. It is best cleaned with warm, soapy water and a soft brush. Like peridot, it is advisable to avoid harsh chemicals, ultrasonic cleaners, and steam cleaners, especially if the stone has been treated or dyed to enhance its bands.
Conclusion
The three birthstones of August—peridot, spinel, and sardonyx—offer a remarkable diversity that truly reflects the richness of the summer month. From the ancient, protective bands of sardonyx to the solar-powered glow of peridot and the revitalizing brilliance of spinel, each gem provides a unique connection to history, science, and personal meaning. This trio allows those born in August not only to choose a stone that fits their aesthetic but also to embrace a multifaceted legacy of gemstone lore. Whether drawn to the vibrant green of peridot, the dazzling array of colors in spinel, or the classic elegance of sardonyx, August-born individuals have a wealth of beautiful and significant options to celebrate their birth.