August boasts a unique distinction among birthstones: not one, but three gemstones represent the month – peridot, spinel, and sardonyx. While peridot and sardonyx have historical precedence, spinel was officially added to the list in 2016 by the American Gem Trade Association (AGTA) and Jewelers of America (JA), acknowledging its beauty and distinct gemological properties. This article will delve into the history, geological origins, properties, and symbolism of each of these August birthstones, offering a comprehensive overview for enthusiasts and those seeking to understand the significance of these captivating gems.
History and Lore
The history of August birthstones is a fascinating journey through ancient beliefs and evolving gemological understanding. Sardonyx holds the longest claim to the month, with references dating back over 4,000 years. It was prominently featured in ancient Roman seals and signet rings, valued for its ability to resist hot wax, making it ideal for authentication. Biblical texts also mention sardonyx, appearing in the high priest’s breastplate and as one of the foundation stones of Jerusalem, establishing its early importance.
Peridot’s story is intertwined with that of topaz. Ancient sources often used the name “topaz” to refer to what is now known as peridot, particularly stones found on the Red Sea island of Topazios. Some historians even suggest that Cleopatra’s famed emerald collection may have largely consisted of peridot, highlighting its historical allure and frequent misidentification. Throughout history, peridot was believed to possess protective qualities, warding off nightmares, evil, and enchantments. Ancient Hawaiians attributed peridot to the tears of the goddess Pele, brought to the surface by volcanic activity.
Spinel’s history is marked by a case of mistaken identity. For centuries, it was frequently misidentified as ruby, particularly red spinel. Many famous “rubies” in royal collections, including the Black Prince’s Ruby in the British Crown Jewels, the Timur Ruby, and Catherine the Great’s Ruby, were later determined to be spinels. It wasn’t until a few hundred years ago that mineralogists were able to definitively distinguish between the two gemstones. This historical confusion adds to spinel’s intriguing story and underscores its inherent beauty, often rivaling that of ruby.
Geological Formation and Sources
Each of these August birthstones originates through distinct geological processes and is found in specific locations around the world. Peridot, a variety of the mineral olivine, is formed under extreme conditions. It can be found in hardened lava, carried from deep within the Earth’s mantle, and even in meteorites originating from outer space.
Spinel forms in metamorphic rocks and alluvial deposits. A significant discovery in Tanzania in 2007 yielded spinels in a range of colors, including pinkish-red, orangy-red, purple, and even rare blue hues colored by cobalt.
Sardonyx, a combination of chalcedony varieties – sard and onyx – forms in layered sedimentary rocks. The distinctive banding of brownish-red sard and white or black onyx creates its unique appearance.
Gemological Properties
The gemological properties of peridot, spinel, and sardonyx differ significantly, contributing to their individual characteristics and appeal.
Peridot: This gem is the yellowish-green to greenish-yellow variety of olivine. Its color is determined by the amount of iron present in the stone. While the most desirable peridots exhibit a brilliant, pure green hue, the color can range from yellowish-green to olive green.
Spinel: Spinel is a durable gemstone, registering 8 on the Mohs scale of hardness. It is known for its vibrant colors, including red, pink, purple, and a rare, vivid blue caused by cobalt. It is stable when exposed to light and chemicals, though high heat can cause some colors to fade.
Sardonyx: Sardonyx is a cryptocrystalline variety of quartz, composed of alternating bands of sard (brownish-red to brown) and onyx (typically white or black). Its banded appearance makes it a popular choice for carving cameos and intaglios.
The following table summarizes key gemological properties:
| Gemstone | Chemical Formula | Color | Hardness (Mohs) | Luster |
|---|---|---|---|---|
| Peridot | (Mg, Fe)₂SiO₄ | Yellowish-green to Green | 6.5 - 7 | Vitreous |
| Spinel | MgAl₂O₄ | Red, Pink, Purple, Blue | 8 | Vitreous |
| Sardonyx | SiO₂ | Banded Red & White/Black | 6.5 - 7 | Waxy |
Symbolism and Metaphysical Beliefs
Throughout history, each of these August birthstones has been attributed with specific meanings and metaphysical properties. Traditionally, peridot symbolized strength and was believed to protect against negative energies. Sardonyx was valued for its grounding properties and association with courage and protection.
Spinel, according to author Judy Hall, possesses refreshing properties and can renew energy, aiding perseverance through difficult tasks. It is also believed to encourage humility in victory. Red spinel, like other blood-colored stones, is often associated with the heart.
Care and Cleaning
Proper care is essential to maintain the beauty of these August birthstones. Spinel, with its hardness of 8, is durable enough for everyday wear in rings and other jewelry. Ultrasonic and steam cleaners can be used, but caution should be exercised if the stone contains fractures. Warm soapy water is always a safe cleaning alternative. Spinel is stable when exposed to light and chemicals, but prolonged exposure to high heat can cause some colors to fade.
Peridot and sardonyx, with a Mohs hardness of 6.5-7, require more gentle care. Avoid harsh chemicals and abrasive cleaners. Cleaning with warm, soapy water and a soft cloth is recommended.
Conclusion
The August birthstones – peridot, spinel, and sardonyx – represent a rich tapestry of history, geological wonder, and symbolic meaning. From the ancient origins of sardonyx to the historical misidentification of spinel and the volcanic origins of peridot, each gem offers a unique story. The addition of spinel as a modern August birthstone in 2016 expands the choices available to those born in this month, offering a diverse range of colors and properties to suit individual preferences. Whether chosen for their beauty, historical significance, or perceived metaphysical benefits, these three gemstones continue to captivate and inspire.