The month of August holds a distinct position in the modern birthstone calendar, uniquely offering not one, but three official gemstones for those born in its warmth. This multiplicity—comprising peridot, spinel, and sardonyx—reflects a rich tapestry of geological diversity, historical evolution, and cultural symbolism. While the traditional birthstone for August is sardonyx, the addition of peridot in the early 20th century and spinel in 2016 has provided August-born individuals with a spectrum of choices ranging from vibrant green to deep red and banded earth tones. Each stone tells a unique story, from the volcanic origins of peridot and its ancient confusion with emeralds, to the underappreciated beauty of spinel, often mistaken for ruby, and the ancient protective power of sardonyx. This article provides a comprehensive gemological and historical analysis of these three captivating stones, exploring their origins, properties, and enduring significance.
The Historical Evolution of August's Birthstones
The designation of birthstones for specific months has undergone significant evolution, with August serving as a prime example of this progression. The journey began with sardonyx, the original August birthstone, whose association with the month dates back over four millennia. Its prominence in ancient civilizations established the foundational link between August and gemstones.
In 1912, the National Association of Jewelers (now known as Jewelers of America) standardized the modern birthstone list. This list designated peridot as an official August birthstone, recognizing its vibrant color and growing popularity. For many years, these two stones—sardonyx and peridot—served as the primary options. However, the desire for greater variety in color, availability, and affordability led to further updates. In 2016, the American Gem Trade Association (AGTA) added spinel to the official list, solidifying the tripartite nature of August's birthstones.
This expansion highlights a practical consideration within the gem trade: offering consumers more choices. Yet, it also underscores the unique historical and symbolic weight each stone carries. Sardonyx represents the ancient tradition; peridot brings a distinct geological narrative and a history of being mistaken for other gems; and spinel offers a story of rediscovery, correcting centuries of misidentification with ruby. Together, they form a triumvirate that caters to a wide range of aesthetic preferences and personal connections.
Peridot: The Gem of the Sun
Peridot stands out among the August birthstones for its unique genesis and singular color range. As the gem variety of the mineral olivine, peridot is chemically composed of magnesium iron silicate. Its most defining characteristic is its color, which ranges from a yellowish-green to a deep olive hue. Unlike many other gemstones that can appear in a rainbow of colors, peridot is found exclusively in shades of green. This consistent color is derived from its iron content.
Origins and Formation
The formation of peridot occurs under conditions of extreme heat and pressure deep within the Earth’s mantle. What makes this gemstone particularly fascinating is the manner in which it reaches the surface. Peridot is brought to the crust through volcanic activity, often found in hardened lava that carries it from the mantle. In a truly extraterrestrial context, peridot has also been discovered in meteorites that have fallen to Earth, making it one of the few gems found in outer space.
Historically, the primary source of peridot was the volcanic island of Zabargad (also known as St. John’s Island) in the Red Sea. Mining on this island dates back over four thousand years, and the peridot extracted here was the source of the gems found in ancient Egyptian jewelry. The ancient Egyptians held this stone in exceptionally high regard, referring to it as the "gem of the sun." They believed it offered protection against the terrors of the night and warded off evil spirits. The Romans, too, prized peridot, calling it the "evening emerald" because its vibrant green color remained visible and lustrous even under artificial light, a property that distinguishes it from many other green gemstones.
Historical Confusion and Identification
Throughout history, peridot has frequently been mistaken for other precious green stones, most notably emerald. The Shrine of the Three Holy Kings in Germany’s Cologne Cathedral is adorned with 200 carats of gems that were long believed to be emeralds but are now identified as peridot. This confusion extends to historical speculation regarding Cleopatra’s famous emerald collection; some historians now theorize that the stones in her collection may actually have been peridot.
The name "peridot" itself is believed to derive from the Arabic word faridat, meaning "gem." Its consistent green hue, which does not vary to blue or other secondary colors like emerald, is a key identifier for gemologists. While topaz was also a point of confusion—particularly because the Red Sea island of Topazios, a source of the name "topaz," actually produced peridot—the distinct properties of peridot have allowed it to carve out its own identity in the gemological world.
Spinel: The Underappreciated Beauty
Spinel, the most recent addition to the August birthstone family, has a history intertwined with that of ruby. For centuries, red spinel was so frequently confused with ruby that it often commanded similar value and was set in royal regalia without distinction. It was only with the advancement of gemological science that spinel was recognized as a distinct mineral species with its own unique properties.
Distinct Properties and Color Range
Chemically, spinel is magnesium aluminum oxide, a composition that distinguishes it from ruby, which is corundum (aluminum oxide). While red is the most famous and sought-after color for spinel—often described as a "stoplight" red or a vibrant "balas ruby" hue—spinel actually occurs in a wide array of colors. These include vibrant pinks, oranges, and even blues, with some blue spinels exhibiting a color reminiscent of fine sapphires. Black spinel is also known. This versatility in color makes spinel an attractive option for jewelry buyers seeking variety.
A History of Mistaken Identity
The confusion between spinel and ruby is responsible for some of history’s most famous gemstone mix-ups. The "Black Prince’s Ruby," a massive red stone set in the British Imperial State Crown, is actually a red spinel. Similarly, the "Timur Ruby," also part of the British Crown Jewels, is a spinel. These stones were once believed to be rubies, highlighting the visual similarity between the two gems in their raw, uncut forms.
Despite being underappreciated for much of history, spinel is now celebrated for its excellent hardness (8 on the Mohs scale), brilliance, and the fact that it is generally more affordable than ruby or sapphire. Its addition to the August birthstone list in 2016 was a nod to both its beauty and its corrected place in gemological history.
Sardonyx: The Ancient Protector
Sardonyx is the oldest of the three August birthstones, with a documented history spanning more than 4,000 years. It is a variety of chalcedony, which is a cryptocrystalline form of quartz, specifically a composite of sard and onyx. Its defining feature is its banded appearance, characterized by alternating layers of reddish-brown sard and black or white onyx.
Geological Formation and Appearance
Sardonyx forms when layers of sard and onyx grow simultaneously within the host rock, creating the distinct bands that make the stone so recognizable. The color contrast between the reddish-brown layers and the white or black bands can range from subtle to striking, depending on the thickness and opacity of the layers. This banded structure is not merely decorative; it is central to the stone’s historical and symbolic use.
Historical Significance and Symbolism
In the ancient world, sardonyx was highly valued in Egypt, Greece, and Rome. Its durability and distinct banding made it ideal for creating seals, amulets, and cameos. The stone’s appearance was believed to symbolize strength, protection, and clarity of thought. Roman soldiers would often wear sardonyx rings or amulets into battle, believing the stone would grant them courage and shield them from harm.
As the original August birthstone, sardonyx carries the weight of ancient tradition. Its association with protection and strength has persisted through the centuries, making it a meaningful choice for those who value historical continuity and the lore of ancient talismans.
Gemological Properties: A Comparative Overview
To better understand the physical characteristics of the three August birthstones, the following table outlines their key gemological properties based on the provided sources.
| Gemstone | Mineral Species | Chemical Composition | Hardness (Mohs Scale) | Color Range |
|---|---|---|---|---|
| Peridot | Olivine | Magnesium Iron Silicate | Not explicitly stated | Yellowish-green to olive green |
| Spinel | Spinel | Magnesium Aluminum Oxide | 8 | Red, pink, orange, blue, black |
| Sardonyx | Chalcedony (Quartz) | Silicon Dioxide | Not explicitly stated | Banded reddish-brown and black/white |
Note: The hardness of peridot and sardonyx is not explicitly detailed in the provided sources. Peridot is generally known to be around 6.5-7 on the Mohs scale, and sardonyx (quartz) is 7, but this information is derived from external gemological knowledge and is not included in the provided text. The table strictly adheres to the properties mentioned in the sources.
Symbolism and Metaphysical Beliefs
The symbolism attached to the August birthstones is as varied as the stones themselves. Each gem has accumulated a unique set of beliefs and meanings over centuries of human interaction.
- Peridot: Associated with the sun, peridot was believed by the Egyptians to bring health, happiness, and protection from nightmares. Its uplifting green color is seen as a symbol of life, nature, renewal, and good health. It is often described as a stone that radiates positive energy and warmth.
- Spinel: While the sources do not detail specific metaphysical beliefs for spinel, its history as a stand-in for ruby suggests it inherited the properties associated with that stone, such as vitality and passion. Its modern status as a distinct gem allows it to be appreciated for its own brilliance and durability.
- Sardonyx: The symbolism of sardonyx is directly linked to its banded appearance and historical use in seals and amulets. It is strongly associated with strength, protection, and clarity of thought. It was believed to bring stability and courage to the wearer, making it a popular stone for warriors and orators in ancient times.
Care and Maintenance
Proper care is essential for maintaining the beauty and longevity of any gemstone. The durability of each August birthstone varies, dictating specific cleaning and handling guidelines.
- Peridot: Due to its composition and relative softness compared to spinel or sardonyx, peridot requires careful handling. It is susceptible to scratches and should be stored separately from harder gems. Cleaning with warm, soapy water and a soft brush is recommended. Ultrasonic and steam cleaners should be avoided.
- Spinel: With a hardness of 8 on the Mohs scale, spinel is quite durable and resistant to scratching. It can generally withstand ultrasonic cleaning, though it is always wise to check for any fractures or inclusions first. Warm, soapy water is a safe and effective method for routine cleaning.
- Sardonyx: As a variety of quartz, sardonyx has a hardness of 7, making it reasonably durable. It can be cleaned with warm, soapy water and a soft brush. It is less prone to scratching than peridot but should still be stored carefully to avoid abrasion from harder stones.
Conclusion
The birthstones of August—peridot, spinel, and sardonyx—offer a remarkable diversity that reflects the month's vibrant energy. From the solar-powered lore of peridot and its deep-earth origins to the rediscovered glory of spinel and the ancient protective power of sardonyx, each stone provides a unique connection to history, geology, and personal expression. This trio ensures that anyone born in August can select a gem that resonates with their individual style, whether they are drawn to the lush green of the evening emerald, the fiery brilliance of the mistaken ruby, or the timeless bands of the ancient talisman. Together, they represent a rich heritage that continues to captivate gemstone enthusiasts, jewelry buyers, and students of gemology alike.