The month of August is uniquely distinguished in the world of gemology by possessing three official birthstones: Peridot, Spinel, and Sardonyx. While many months have adopted multiple gems over time, August stands out because these stones represent a distinct historical progression—from the ancient banded chalcedony of antiquity to the vibrant greens of volcanic origins and the dazzling variety of the "great imposter." For the August-born individual, this triad offers an unparalleled spectrum of color, lore, and durability, bridging the peak of summer with the promise of autumn.
Among these, Peridot has emerged as the primary or "main" birthstone for the month, celebrated for its singular, vibrant hue and deep historical roots. However, the presence of Spinel and Sardonyx ensures that August offers a birthstone for every aesthetic and historical inclination. This article explores the geological origins, gemological properties, historical significance, and metaphysical beliefs associated with these three remarkable gems, providing a definitive resource for collectors, jewelers, and enthusiasts alike.
The Historical Triad: From Antiquity to the Modern Era
The assignment of birthstones to months has evolved significantly over centuries, but August’s collection is particularly layered. The journey begins with Sardonyx, the original August birthstone, which has been documented in use for over 4,000 years. Ancient civilizations, particularly the Romans, prized this banded variety of chalcedony. The stone’s distinctive layers of red sard and white onyx were believed to capture the fiery energy of the harvest month, offering balance and protection.
However, as gemological knowledge expanded and trade routes opened, Peridot began to gain prominence. Often confused with emeralds and topaz throughout history, Peridot’s true identity was eventually distinguished, leading to its designation as the primary modern birthstone for August. In the late 20th century, specifically in 2016, the American Gem Trade Association (AGTA) added Spinel to the list of official August birthstones. This decision acknowledged Spinel’s durability and the growing appreciation for its wide range of colors, while also rectifying centuries of historical confusion where red spinel was mistaken for ruby.
This evolution reflects a shift in the jewelry market toward consumer choice and the recognition of gemstones that offer both beauty and practicality for everyday wear. Today, the availability of these three stones ensures that August is represented not by a single color or form, but by a rich palette ranging from earthy reds and whites to brilliant greens and deep blues.
Peridot: The Gem of the Sun
Geological Formation and Sources
Peridot is the gem variety of the mineral olivine, with the chemical formula (Mg,Fe)₂SiO₄. Unlike many gemstones that form in the Earth’s crust, Peridot is formed deep within the Earth’s mantle. It is brought to the surface by volcanic activity and is occasionally found in meteorites that have fallen to Earth, a rare occurrence that underscores its extraterrestrial potential.
The gem’s formation under extreme conditions is a point of fascination for geologists. It can be found in hardened lava carried from deep within the mantle and in peridotite inclusions in black rock. Significant sources of Peridot include the San Carlos Apache Reservation in Arizona, which produces a large portion of the world’s supply. Other notable mining locations mentioned in historical and trade records include China, Myanmar (Burma), and Pakistan. The gem is also notably found on the Red Sea island of Topazios, a location that historically caused confusion regarding the stone’s identity (it was often mistaken for topaz).
Gemological Properties
Peridot is prized for its distinctive color, which ranges from yellowish-green to greenish-yellow. It is one of the few gemstones that occurs in only one color family—olive green—though the intensity and saturation vary based on the iron content. The most valued hue is a rich, pure green without brown or yellow modifiers.
- Hardness: On the Mohs scale of hardness, Peridot ranks between 6.5 and 7. While durable enough for jewelry, it requires slightly more care than harder stones like sapphire or diamond.
- Clarity: Peridot typically contains inclusions. However, these inclusions are often accepted as part of the stone's character and do not usually detract from its value unless they compromise the stone's durability or transparency.
- Refractive Index: As a member of the olivine group, it has a refractive index that contributes to its vitreous luster.
History and Lore
The history of Peridot is rich and often shrouded in misidentification. Ancient Egyptians referred to it as the "gem of the sun," believing it protected its wearer from the terrors of the night. It was a favorite stone of pharaohs and was mined on the island of Zabargad (Topazios) as early as 1500 B.C.
A significant historical anecdote involves the Shrine of the Three Holy Kings in Germany’s Cologne Cathedral. The 200 carats of gems decorating the shrine were believed for centuries to be emeralds but have since been identified as Peridot. This misidentification was common; some historians speculate that Cleopatra’s famous emerald collection may actually have been Peridot. The confusion stemmed from the fact that Peridot and emerald can look similar, though Peridot generally has a brighter, less saturated green.
Symbolism and Metaphysical Beliefs
Peridot is strongly associated with harmony, healing, and emotional strength. The birthstone meaning for August, specifically regarding Peridot, represents renewal, growth, and positive transformation. It is believed to ward off evil spirits and nightmares, a belief held by ancient Egyptians who would place Peridot amulets on the necks of the deceased to ensure safe passage.
In modern metaphysical circles, Peridot is known as a stone of compassion. It is believed to bring good luck, peace, and emotional clarity to the wearer. Many believe that wearing Peridot jewelry can reduce stress and enhance creativity, making it a popular choice for those seeking emotional balance.
Spinel: The Great Imposter Turned Star
Geological Formation and Sources
Spinel is a magnesium aluminum oxide with the chemical formula MgAl₂O₄. It forms in the metamorphic rocks of marble and alluvial deposits. For centuries, Spinel was the "great imposter," specifically the red varieties that were mistaken for rubies. The "Black Prince’s Ruby" in the British Imperial State Crown and the "Timur Ruby" are actually massive red Spinels.
Despite its history of being overshadowed by the ruby, Spinel has a distinct identity. It is found in various locations, including Myanmar (Burma), Sri Lanka, and Thailand. While red is the most famous color, Spinel actually occurs in a wide range of hues, including vibrant pinks, blues, and purples.
Gemological Properties
Spinel is an excellent gemstone for jewelry due to its durability and lack of cleavage. * Hardness: It rates an 8 on the Mohs scale, making it harder and more durable than Peridot. This superior hardness makes it an excellent choice for rings and bracelets that are subject to daily wear. * Color: While the "ruby-like" red is the benchmark, the gem is celebrated today for its brilliant blues and hot pinks. * Clarity: High-quality Spinel is typically clean, lacking the inclusions often found in Peridot or Ruby.
History and Lore
The history of Spinel is inextricably linked to that of Ruby. The confusion arose because both gems are found in the same geological environments and share similar physical properties, such as color and specific gravity. It was not until advancements in gemology in the 18th and 19th centuries that the two were definitively distinguished chemically and physically.
In the context of birthstones, Spinel is a relatively new addition, but it has quickly gained favor. It represents a modernization of the August birthstone list, offering an alternative that is rarer than many realize and possesses a brilliance that rivals diamonds.
Symbolism
Because of its varied palette, Spinel is associated with revitalizing energy. Historically, because it was mistaken for Ruby, it inherited some of Ruby’s lore regarding prosperity and energy, but modern interpretations suggest it is a stone of hope and renewal. It is said to help one overcome lethargy and find new motivation in life.
Sardonyx: The Ancient Warrior’s Stone
Geological Formation and Sources
Sardonyx is a variety of chalcedony, which is a cryptocrystalline form of silica (SiO₂). It is composed of layers of sard (a reddish-brown chalcedony) and onyx (white or black banded chalcedony). These bands are created by the oxidation of iron impurities within the silica gel during the stone's formation.
Sardonyx is found primarily in India, though deposits have also been located in Germany, Brazil, and the United States. The stone is cut in cabochons (domed cuts) to best display its distinct banding.
Gemological Properties
- Hardness: Like other varieties of quartz/chalcedony, Sardonyx has a hardness of 7 on the Mohs scale, making it quite durable.
- Composition: It is silicon dioxide, identical to quartz but with a microcrystalline structure.
- Appearance: The visual appeal of Sardonyx lies in the contrast between the reddish-brown layers of sard and the white layers of onyx.
History and Lore
Sardonyx is the oldest of the three August birthstones, with a history dating back over 4,000 years. It was a favorite stone of the ancient Greeks and Romans, who used it extensively for cameos and intaglios (engraved gems). The Romans believed that Sardonyx captured the fiery energy of August, representing the harvest.
In ancient lore, Sardonyx was considered a stone of courage and protection. Warriors would wear amulets of Sardonyx into battle, believing it would grant them strength and shield them from harm. It was also associated with clear communication and was used by orators to enhance their speeches.
Care and Cleaning
Maintaining the beauty of August’s birthstones requires an understanding of their physical properties. While all three are suitable for jewelry, their care requirements differ.
Peridot (Hardness 6.5-7): Peridot is moderately durable but can be scratched by harder stones. It is best cleaned with warm, soapy water and a soft brush. Avoid ultrasonic cleaners and steam cleaning, as the stone’s inclusions can be sensitive to heat and sudden temperature changes. Store Peridot separately to prevent scratching by diamonds or sapphires.
Spinel (Hardness 8): Spinel is quite durable and generally safe for most cleaning methods. It can be cleaned with warm soapy water, ultrasonic cleaners, and steam cleaners. Its hardness makes it an excellent choice for everyday rings and earrings.
Sardonyx (Hardness 7): As a variety of chalcedony, Sardonyx is durable but can be susceptible to chipping if struck hard due to its conchoidal fracture. Warm, soapy water and a soft cloth are the best cleaning methods. Avoid harsh chemicals that could dull the stone's luster.
Conclusion
The August birthstones—Peridot, Spinel, and Sardonyx—offer a diverse array of choices that reflect the richness of the month itself. From the ancient, earthy bands of Sardonyx that recall the harvests of antiquity to the vibrant, solar glow of Peridot and the dazzling variety of Spinel, these gems provide options for every taste and occasion.
Peridot stands as the primary representative, celebrated for its unique color and connection to the Earth's mantle and the stars. Yet, the inclusion of Spinel and Sardonyx ensures that the legacy of August is not limited to a single hue. Whether chosen for their historical significance, their durability, or their purported metaphysical benefits, these three stones remain enduring symbols of summer’s vitality. For the collector and the wearer alike, August’s birthstones represent a heritage of beauty, confusion, and eventual clarification—a journey as captivating as the gems themselves.