August boasts a unique distinction among birthstone months: it possesses not one, but three recognized gemstones – peridot, spinel, and sardonyx. Each stone carries its own rich history, geological origins, and symbolic meaning, offering a diverse range of choices for those born under the August sun. This article will delve into the characteristics of each of these August birthstones, exploring their historical significance, gemological properties, and enduring appeal.
History and Lore
The history of August birthstones is complex, with traditions evolving over time. Sardonyx holds the longest documented history, appearing as early as 4,000 years ago and featuring prominently in ancient civilizations. It was favored by the Romans for creating seals and signet rings, valued for its smooth surface that prevented wax from adhering. Referenced in the Bible, it was included in the high priest’s breastplate and considered one of the foundation stones of Jerusalem.
Peridot’s story is intertwined with historical misidentification. For centuries, it was often confused with topaz and emerald, particularly from sources on the Red Sea island of Topazios, which primarily yielded peridot rather than true topaz. Some historians even suggest that Cleopatra’s famed emerald collection may have largely consisted of peridot. The gem was also believed to ward off nightmares, evil, and enchantments. Ancient Hawaiians connected peridot to the tears of Pele, the goddess of volcanoes, believing the stones were brought to the surface by volcanic activity.
Spinel’s history is more recent in terms of recognition. For centuries, red spinel was mistaken for ruby, particularly in historical jewelry and royal collections. It wasn’t until the 19th century that spinel was definitively classified as a distinct mineral. However, this doesn’t diminish its historical presence; it simply highlights a long-standing case of mistaken identity. A significant discovery in Tanzania in 2007 brought renewed attention to spinel, revealing specimens in a range of colors including pink, orange, purple, and blue, captivating gem collectors.
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 gem-quality olivine, is formed under extreme conditions, often found in hardened lava carried from deep within the Earth’s mantle. It can also be discovered in meteorites, offering a truly extraterrestrial origin. The majority of the world’s peridot supply, estimated at up to 95 percent, comes from the San Carlos Reservation in Arizona. Additional sources include Pakistan, Myanmar, and China. Its association with divergent plate boundaries and hot spots, like Hawaii, further explains its geological occurrence.
Spinel forms in metamorphic rocks and alluvial deposits. Significant spinel deposits are found in Tanzania, where a 2007 discovery yielded a variety of colors. Other sources include Myanmar and Sri Lanka.
Sardonyx is a variety of chalcedony, a cryptocrystalline form of quartz, composed of alternating bands of sard (reddish-brown) and onyx (typically white or black). It forms in volcanic and sedimentary environments. While historical sources are less specifically detailed, its formation is linked to the geological processes that create banded agate and other forms of chalcedony.
Gemological Properties
The three August birthstones differ significantly in their gemological properties, contributing to their unique appearances and durability.
Peridot: This silicate mineral has a chemical formula of (Mg, Fe)2SiO4. It typically exhibits a yellowish-green to greenish-yellow hue. Peridot’s hardness is 6.5-7 on the Mohs scale, making it suitable for most jewelry applications, though it requires some care to avoid scratching.
Spinel: With a chemical formula of Al2O3:Cr, spinel is an oxide mineral. It displays a wide range of colors, including pink, red, blue, and even colorless. Spinel boasts a hardness of 8 on the Mohs scale, making it a durable gemstone ideal for rings and everyday wear. It exhibits a vitreous or subadamantine luster and a white streak. Its specific gravity ranges from 3.97 to 4.05.
Sardonyx: This chalcedony variety is composed of layers of sard and onyx. Its color ranges from brownish-red to dark orange, layered with white or black bands. Sardonyx has a hardness of 6.5-7 on the Mohs scale. It possesses a vitreous luster and a specific gravity of approximately 2.64.
The following table summarizes these properties:
| Gemstone | Chemical Formula | Hardness (Mohs) | Color | Luster |
|---|---|---|---|---|
| Peridot | (Mg, Fe)2SiO4 | 6.5-7 | Yellowish-green to greenish-yellow | Vitreous |
| Spinel | Al2O3:Cr | 8 | Pink to red, blue, colorless | Vitreous, Subadamantine |
| Sardonyx | (SiO2) | 6.5-7 | Banded reddish-brown and white/black | Vitreous |
Symbolism and Metaphysical Beliefs
Throughout history, each of these August birthstones has been attributed with various symbolic meanings and metaphysical properties.
Sardonyx, with its ancient roots, was believed to impart strength and courage. Its banded structure was seen as representing layers of protection.
Peridot has long been associated with strength and protection against negative energies. It was thought to ward off nightmares and evil spirits. Modern interpretations suggest peridot can renew energy and promote perseverance, encouraging humility in victory.
Spinel, according to author Judy Hall, possesses refreshing properties and can revitalize energy, aiding in overcoming challenges. It is also believed to foster humility and acceptance. The various colors of spinel are also associated with different energies; for example, red spinel is linked to the heart and passion.
Care and Cleaning
Proper care is essential to maintain the beauty of these August birthstones. Spinel, with its hardness of 8, is the most durable and can generally withstand ultrasonic and steam cleaning, though caution should be exercised if the stone has fractures. Peridot and sardonyx, with a hardness of 6.5-7, require gentler cleaning methods. Warm, soapy water and a soft brush are recommended for all three stones. High heat should be avoided, as it can cause some colors of spinel to fade.
Conclusion
The August birthstones – peridot, spinel, and sardonyx – represent a fascinating blend of history, geology, and symbolism. From the ancient origins of sardonyx to the recent rediscovery of spinel’s vibrant colors and the often-misidentified history of peridot, these gemstones offer a diverse and compelling selection for those born in the eighth month of the year. Each stone possesses unique properties and a rich cultural legacy, making them treasured additions to any jewelry collection and meaningful symbols of August birthdays.