August boasts a unique distinction among the calendar months: it possesses not one, but three recognized birthstones – peridot, spinel, and sardonyx. While peridot is often considered the primary August birthstone, spinel’s recent addition in 2016 and the historical significance of sardonyx offer a diverse range of choices for those born under this summer month. Each gem carries its own distinct history, geological origins, and symbolic meanings, making August a particularly rich and varied month for gemstone enthusiasts.
A History Intertwined with Misidentification and Rediscovery
The history of August birthstones is marked by instances of mistaken identity and evolving recognition. Peridot, in particular, has a long and fascinating past often shrouded in confusion with other green gems. Ancient scholars, including Pliny the Elder, frequently referred to peridot as “topaz,” a misnomer stemming from the island of Topazios (now Zabargad) in the Red Sea, which was, in fact, a significant source of peridot. Cleopatra herself was believed to have adorned herself with peridot, though these gems were often mistakenly identified as emeralds. This historical confusion continued for centuries, with the name “topaz” being applied to the gem even after the true topaz was recognized as a distinct mineral.
Sardonyx holds the distinction of being the oldest August birthstone, with a history stretching back over 4,000 years. It was prominently featured in ancient civilizations, appearing in the high priest’s breastplate as described in the Bible and serving as a foundational stone of Jerusalem. Ancient Greeks and Romans valued sardonyx for its perceived protective qualities, utilizing it in amulets, cameos, and seals, believing it brought victory in battle and enhanced communication skills.
Spinel, the newest addition to the August birthstone family, experienced a different trajectory. For centuries, red spinel was frequently mistaken for ruby, particularly in historical collections. It wasn’t until the 19th century that spinel was definitively recognized as a separate mineral species. Its inclusion as a modern August birthstone by the Jewelers of America and the American Gem Trade Association in 2016 reflects a growing appreciation for its unique beauty and vibrant colors.
Geological Origins and Global Sources
The formation and sourcing of these three August birthstones vary considerably. Peridot originates from the Earth’s mantle, brought to the surface through volcanic activity or found within pallasite meteorites. These meteorites, containing olivine crystals (the mineral composition of peridot), offer a truly extraterrestrial origin for the gem. While peridot can be found in various locations, significant sources include the United States (particularly the Southwest), Egypt, Myanmar, Brazil, and Vietnam.
Spinel’s geological formation is often associated with metamorphic rocks and marble deposits. It can also be found in alluvial deposits, where it has been eroded from its original source and carried by water. Notable spinel sources include Myanmar, Sri Lanka, Vietnam, and Tajikistan. The diversity of geological settings contributes to the wide range of colors found in spinel.
Sardonyx, a variety of onyx, is formed through the banding of chalcedony, a microcrystalline form of quartz. Its reddish-brown and white banding is a defining characteristic. India is a primary source of sardonyx, but it is also found in Brazil, Uruguay, the United States, and Germany. The formation of sardonyx typically occurs in volcanic lava flows.
Gemological Properties: A Comparative Overview
Each of the August birthstones possesses unique gemological properties that contribute to its distinct appearance and value.
Peridot, with a chemical formula of (Mg,Fe)2SiO4, is a variety of olivine, composed primarily of magnesium and iron. The presence of iron is responsible for its characteristic yellow-green to olive-green color. Peridot typically exhibits a vitreous luster and a hardness of 6.5 to 7 on the Mohs scale.
Spinel, a magnesium aluminum oxide (MgAl2O4), displays a wide range of colors, including red, pink, blue, white, and black. It possesses a vitreous luster and a hardness of 8 on the Mohs scale, making it more durable than peridot.
Sardonyx, a banded variety of chalcedony (SiO2), exhibits a combination of reddish-brown and white layers. It has a waxy luster and a hardness of 6.5 to 7 on the Mohs scale.
The following table summarizes key gemological properties:
| Property | Peridot | Spinel | Sardonyx |
|---|---|---|---|
| Chemical Formula | (Mg,Fe)2SiO4 | MgAl2O4 | SiO2 |
| Color | Yellow-Green | Red, Pink, Blue | Reddish-Brown/White |
| Luster | Vitreous | Vitreous | Waxy |
| Hardness (Mohs) | 6.5 - 7 | 8 | 6.5 - 7 |
| Mineral Group | Olivine | Oxide | Chalcedony |
Symbolism and Metaphysical Beliefs
Throughout history, each of these August birthstones has been attributed with various symbolic meanings and metaphysical properties. Peridot has long been associated with abundance, protection, and positivity. It was believed to ward off evil spirits and bring good fortune to its wearer.
Spinel is often linked to revitalization and renewal, promoting energy and passion. It is thought to encourage positive thoughts and overcome obstacles.
Sardonyx symbolizes strength, courage, and protection. Ancient civilizations believed it enhanced communication skills and brought victory in battle. It was often used in amulets and seals for its protective qualities.
Care and Cleaning
Proper care is essential to maintain the beauty and luster of August birthstones. Peridot, with a hardness of 6.5 to 7, is relatively soft and susceptible to scratches. It should be cleaned with warm, soapy water and a soft brush. Avoid ultrasonic cleaners and harsh chemicals.
Spinel, being harder with a Mohs hardness of 8, is more durable. It can be cleaned with warm, soapy water, a soft brush, and ultrasonic cleaners can be used with caution.
Sardonyx, also with a hardness of 6.5 to 7, requires gentle cleaning with warm, soapy water and a soft brush. Avoid harsh chemicals and prolonged exposure to sunlight, which can fade its color.
Conclusion
The August birthstones – peridot, spinel, and sardonyx – represent a captivating blend of history, geology, and symbolism. From the ancient misidentification of peridot as topaz to the recent recognition of spinel as a distinct gem and the enduring legacy of sardonyx, these stones offer a rich tapestry of lore and beauty. Whether chosen for their aesthetic appeal, their historical significance, or their perceived metaphysical properties, the August birthstones provide a meaningful connection to the natural world and the enduring power of gemstones.