August is a unique month in the gemological calendar, distinguished by not one, but three official birthstones: peridot, sardonyx, and spinel. This trio offers an exceptional breadth of color, history, and symbolism, providing a rich palette for jewelry connoisseurs and those seeking meaningful personal adornments. From the vibrant, sunlit green of peridot to the striking bands of sardonyx and the dazzling array of colors found in spinel, each stone tells a distinct story. Together, they represent themes of vitality, protection, and courage, making them far more than mere decorative elements. This comprehensive guide delves into the physical properties, historical origins, cultural significance, and practical care of August’s celebrated birthstones, drawing upon established gemological data and historical context.
History and Lore of the August Trio
The historical journey of August's birthstones is as diverse as the stones themselves. While peridot and sardonyx have ancient roots, spinel’s recognition is a more recent development, correcting centuries of misidentification.
Peridot: The Ancient "Sun Gem" Peridot, with its signature olive-green hue, is one of the oldest known gemstones. Its history stretches back to the ancient world, where it was highly prized by the Egyptians. They called it the "gem of the sun" and believed it offered protection against nightmares and evil spirits when set in gold. Cleopatra’s famed emerald collection was, in fact, largely composed of peridot, a fact often obscured by historical misidentification. Peridot was also found on the fabled "Emerald Isles" of the Red Sea, the source for many ancient gems. Its association with light and positivity has endured through the ages, solidifying its status as a symbol of renewal and good fortune.
Sardonyx: The Stone of Courage Sardonyx, a variety of banded chalcedony, boasts a history deeply intertwined with ancient Rome and Greece. Its name derives from the Greek words sard (referencing the reddish-brown sard layer) and onyx (meaning "veined gem"). This stone was a favorite for signet rings and cameos, as its distinct bands of color provided a natural canvas for intricate carving. The Romans valued sardonyx for its perceived ability to grant courage and strength in battle, often carving amulets and seals with the image of Mars, the god of war. It was believed to protect the wearer from harm and to promote clear, confident communication, making it a powerful talisman for public speakers and leaders.
Spinel: The Great Impostor Spinel’s history is perhaps the most dramatic, long living in the shadow of more famous gems. For centuries, magnificent red and pink spinels were mistaken for rubies. The most famous example is the "Black Prince's Ruby," a colossal 170-carat red spinel that adorns the British Imperial State Crown. It was originally owned by Edward, the Black Prince, in the 14th century and was believed to be a ruby until modern gemology could definitively distinguish the two. Spinel was also a major source of confusion in the crown jewels of various European and Asian monarchs. It was only in the late 18th century that spinel was formally recognized as a distinct mineral species. Its inclusion as an official August birthstone in 2016 by the American Gem Trade Association (AGTA) was a nod to its beauty and its long, albeit mistaken, association with royalty.
Geological Formation and Sources
Understanding where these gemstones originate provides insight into their rarity and unique characteristics. Each of the August stones forms under different geological conditions and is sourced from specific regions around the globe.
Peridot Peridot is unique among gemstones as it is found not only in the Earth's crust but also in the upper mantle. It is formed deep within the Earth and brought to the surface by volcanic activity. This is why it is often found in volcanic regions and in meteorites (pallasite meteorites), where it has been identified as extraterrestrial peridot. Major sources for gem-quality peridot include Pakistan, Arizona (USA), Mexico, and Myanmar. The finest specimens often exhibit a rich, saturated olive-green color with minimal inclusions.
Sardonyx As a variety of chalcedony (a microcrystalline form of quartz), sardonyx forms in volcanic rock cavities. Its characteristic banding is the result of alternating layers of sard (a reddish-brown chalcedony) and onyx (a white or black chalcedony) deposited over long periods. Key sources for sardonyx include India, Brazil, Germany, and the United States. The quality of the banding and the sharpness of the contrast between the layers are critical factors in determining its value for use in cameos and intaglios.
Spinel Spinel crystals form in two primary geological environments: pegmatites and marble deposits. The most prized spinels, particularly the vibrant reds and pinks, are often found in the marble quarries of Myanmar (Burma), a region historically famous for its "ruby" mines. Other significant sources include Sri Lanka and Vietnam. Spinel's formation requires the presence of magnesium and aluminum under high-temperature and high-pressure conditions, which are met in these specific metamorphic and igneous environments.
Gemological Properties
A detailed understanding of the gemological properties of these stones is essential for both gemologists and jewelry buyers. These properties, including color, clarity, hardness, and chemical composition, directly influence a stone's value, durability, and suitability for different types of jewelry. The following table provides a comparative overview of the key properties of each August birthstone.
| Property | Peridot | Sardonyx | Spinel |
|---|---|---|---|
| Color | Yellow-green to deep olive green | Red-brown and white bands | Red, pink, blue, colorless |
| Clarity | Typically transparent | Often opaque or semi-transparent | Often transparent to semi-transparent |
| Hardness (Mohs) | 6.5–7 | 6–7 | 8 |
| Chemical Formula | MgFeSiO₄ | SiO₂ | MgAl₂O₄ |
| Luster | Vitreous | Waxy to vitreous | Vitreous |
| Origin | Volcanic regions | Chalcedony deposits | Pegmatite and marble deposits |
Peridot exhibits a vitreous luster and its characteristic green color is due to the presence of iron. With a hardness of 6.5 to 7 on the Mohs scale, it is durable enough for most jewelry, though care should be taken to avoid sharp blows. Its transparency makes it ideal for faceted cuts that maximize its brilliance.
Sardonyx, with a hardness of 6 to 7, is a relatively durable stone. Its waxy to vitreous luster and opaque nature make it exceptionally well-suited for carved designs like cameos and intaglios, where the distinct color bands can be used to create dramatic contrast in the finished piece.
Spinel is the most durable of the trio, with a hardness of 8 on the Mohs scale. This makes it an excellent choice for all types of jewelry, including rings and bracelets that are subject to daily wear. Its vitreous luster and wide range of vibrant colors, combined with its durability, make it a versatile and highly desirable gemstone.
Symbolism and Metaphysical Beliefs
Each of August's birthstones is associated with specific symbolic meanings and metaphysical properties that have been passed down through generations. These beliefs, rooted in ancient lore and modern interpretations, generally emphasize themes of protection, courage, and vitality.
Peridot: The Stone of Prosperity and Protection Peridot is often associated with prosperity, growth, and protection. It is believed to bring good fortune and to ward off negative energies and envy. In ancient Egypt, it was used to create amulets that were thought to protect the wearer from nightmares and evil spirits. In modern times, peridot is seen as a symbol of renewal and new beginnings, making it a popular choice for those seeking a fresh start or new opportunities. Its connection to the sun imbues it with positive, life-affirming energy.
Sardonyx: The Stone of Courage and Communication Sardonyx is known for its ability to promote courage, strength, and stamina. It is believed to help the wearer overcome fear, especially in challenging situations, and to communicate with clarity and confidence. As a stone of protection, it was historically carried as a talisman to guard against accidents and ill will. Its layered structure is symbolic of building a strong foundation and mastering one's emotions.
Spinel: The Stone of Renewal and Vitality Spinel is associated with revitalizing energy and overcoming lethargy. It is believed to inspire passion and hope, helping to renew one's enthusiasm for life. The red and pink varieties are linked to the root and heart chakras, promoting physical energy and emotional balance. Historically, as a stand-in for ruby, it inherited many of the ruby's associations with vitality, passion, and wealth, but with its own unique energy of resilience and endurance.
Care and Cleaning
Proper care is essential to maintain the beauty and longevity of any gemstone. The physical properties of peridot, sardonyx, and spinel dictate the best methods for cleaning and storing them.
Peridot Due to its moderate hardness (6.5-7) and potential for cleavage, peridot requires careful handling. It is susceptible to scratches and should be stored separately from other jewelry. To clean peridot, use warm, soapy water and a soft brush. Avoid ultrasonic cleaners and steam cleaners, as the heat and vibrations can cause damage. Sudden temperature changes should also be avoided.
Sardonyx As a variety of quartz, sardonyx is relatively stable and can be cleaned with warm, soapy water and a soft cloth or brush. It is generally safe for ultrasonic cleaning, but it is always best to exercise caution. Its durability makes it suitable for everyday wear, especially in protective settings like cabochons or carvings.
Spinel Spinel is one of the most durable and easy-to-care-for gemstones. With a hardness of 8 and good toughness, it is highly resistant to scratching and abrasion. It can be safely cleaned using warm, soapy water, an ultrasonic cleaner, or a steam cleaner. Its stability makes it an ideal choice for all forms of jewelry, requiring minimal special care beyond standard cleaning practices.
Conclusion
The three birthstones of August—peridot, sardonyx, and spinel—offer a remarkable diversity that makes this month truly special. Peridot provides a vibrant splash of green with a history tied to ancient royalty and celestial origins. Sardonyx offers a classic, banded beauty steeped in the courage and artistry of the Roman Empire. Spinel, the great impostor turned celebrated gem, dazzles with its exceptional hardness and a spectrum of colors that rivals any precious stone. Together, they provide a wide array of choices for personal adornment, each carrying a unique story of geological formation, historical significance, and symbolic power. Whether chosen for its vibrant color, its rich lore, or its remarkable durability, an August birthstone is a timeless and meaningful treasure.