For individuals born on August 23, the tradition of birthstones offers a unique duality. While the entire month of August is associated with three official gemstones—peridot, spinel, and sardonyx—those born specifically on the twenty-third day are traditionally linked to the vibrant green of peridot and the banded layers of sardonyx. These two stones, though vastly different in appearance and composition, provide a rich narrative of geological marvels, ancient history, and enduring symbolism.
Peridot, with its distinctive lime-green hue, is a gem formed under extreme conditions, found deep within the Earth's mantle and occasionally delivered to us from outer space. Sardonyx, a variety of chalcedony, boasts a history stretching back over 4,000 years, prized by Roman legions and Greek artisans for its durability and striking bands. This article explores the geological origins, gemological properties, historical lore, and practical care for these two remarkable August birthstones.
The Legacy of Peridot: The Gem of the Sun
Peridot is the primary modern birthstone for August, a status solidified by the National Association of Jewelers in 1912. It is a gem-quality variety of the mineral olivine, a silicate of magnesium and iron. Its color is its most defining characteristic, ranging from a bright, yellowish-green to a deeper olive tone. Unlike many other gemstones that occur in a spectrum of colors, peridot is found exclusively in shades of green, with the hue determined by the specific iron content within its crystal structure.
The name "peridot" is widely believed to derive from the Arabic word faridat, meaning "gem." This etymology hints at its long-standing value in Middle Eastern cultures. However, the history of peridot is often entangled with mistaken identity. For centuries, this August birthstone was confused with other precious green stones, specifically emeralds and topaz. Historical records indicate that many "emeralds" set in medieval European cathedral treasures were later identified as peridots. This confusion extended to the Red Sea island of Topazios, a location historically cited as a source of topaz, which actually produced peridot.
The allure of peridot dates back to ancient Egypt, where it was known as the "gem of the Sun." Egyptian pharaohs held this stone in high regard, believing it offered protection against evil spirits and nightmares. The Egyptians mined peridot on the island of Zabargad (formerly Topazios) in the Red Sea, a source that supplied the ancient world with these glowing green gems. The stone was so prized that it was often worn as an amulet to ward off enchantment and bring happiness and strength to the wearer.
Beyond its historical significance, peridot possesses a unique geological origin story. It is one of the few gemstones that are not formed in the Earth's crust, but rather in the Earth's mantle. Extreme conditions, including high heat and pressure, create this gem deep within the planet. It is brought to the surface through volcanic activity, making active volcanic regions prime locations for mining. In a truly cosmic twist, peridot has also been discovered in pallasite meteorites—types of stony-iron meteorites that formed in the early solar system. This rare extraterrestrial occurrence makes peridot one of the only gemstones found naturally in outer space, adding to its mystique and desirability.
The Enduring Appeal of Sardonyx: The Original August Stone
While peridot may be the most recognized August birthstone today, sardonyx holds the distinction of being the original birthstone for the month, with a history of use that spans more than 4,000 years. Sardonyx is a banded variety of chalcedony, which itself is a fibrous form of quartz. It is composed of alternating layers of sard (a reddish-brown variety of chalcedony) and onyx (a black-and-white banded variety).
The visual appeal of sardonyx lies in its distinct, parallel bands of color. These natural lines are the result of different mineral impurities being deposited in alternating layers during the gem's formation. Artisans have long capitalized on this banding, cutting the stone in "cameos" or "intaglios" to create striking contrasts between the layers. In a cameo, the design is carved in relief with the upper layer being a lighter color (often white onyx) set against a darker background (sard), while an intaglio features an incised design cut into the stone.
Historically, sardonyx was immensely popular in ancient Rome. Roman soldiers wore rings and amulets made of sardonyx, believing the stone would protect them in battle and grant them courage. This association with strength and protection made it a favorite for signet rings, which were used to press a seal into hot wax for authenticating documents. The durability of sardonyx, combined with its ability to hold a sharp, detailed carving, made it ideal for this purpose.
The symbolism of sardonyx extends beyond military prowess. It was also believed to bring happiness, good fortune, and clear communication. In many ancient cultures, sardonyx was used in amulets to promote eloquence, making it a talisman for public speakers and orators. Its reputation as a stone of strength and stability has persisted through the ages, securing its place as a traditional birthstone that offers a historical counterpoint to the more modern peridot.
Gemological Properties and Identification
Understanding the physical and chemical properties of these August 23rd birthstones is essential for both appreciation and care.
Peridot Properties
Peridot is a relatively hard and durable gemstone, making it suitable for a variety of jewelry applications, including rings, earrings, and pendants.
- Mineral: Olivine (a magnesium iron silicate)
- Chemical Formula: (Mg, Fe)₂SiO₄
- Hardness: 6.5 to 7 on the Mohs scale. While reasonably durable, it can be susceptible to scratching if worn daily in rings without proper care.
- Crystal System: Orthorhombic
- Refractive Index: 1.65 to 1.69
- Specific Gravity: 3.34
- Luster: Vitreous (glass-like)
- Clarity: Peridot often contains inclusions that are characteristic of the stone. One common type is "lily pads," which are disc-shaped, hollow inclusions that can be filled with gas or liquid. These inclusions can help gemologists distinguish peridot from other green stones like emerald or tourmaline.
Peridot's single-color range means that its value is primarily determined by the intensity and saturation of its green color. The most prized peridots exhibit a rich, pure green without any yellowish or brownish modifiers.
Sardonyx Properties
Sardonyx shares the properties of quartz and chalcedony, known for its toughness and suitability for carved jewelry.
- Mineral: Chalcedony (a microcrystalline variety of quartz)
- Chemical Formula: SiO₂
- Hardness: 6.5 to 7 on the Mohs scale (similar to peridot and other quartz varieties).
- Crystal System: Trigonal (microcrystalline)
- Refractive Index: 1.53 to 1.54
- Specific Gravity: 2.60
- Luster: Waxy to vitreous
- Clarity: Opaque to translucent. The defining feature is its distinct banding, which is considered an essential characteristic rather than a flaw.
The value of sardonyx is based on the sharpness and contrast of its bands. The most desirable stones feature clear, well-defined lines between the reddish-brown sard and the black or white onyx layers.
Symbolism and Metaphysical Beliefs
Throughout history, gemstones have been attributed with various powers and meanings. Peridot and sardonyx are no exception, each carrying a rich tapestry of symbolic associations.
Peridot is often associated with light, positivity, and protection. As the "gem of the Sun," it is believed to bring warmth, energy, and good fortune to its wearer. Ancient lore suggested that peridot could dispel negative emotions, such as envy and jealousy, and instead foster openness and honesty. It is also linked to healing and renewal, thought to strengthen the immune system and cleanse the body of toxins. In modern crystal healing practices, peridot is considered a stone of abundance and prosperity, encouraging growth and new beginnings.
Sardonyx, with its history of use by Roman soldiers, is strongly connected to courage, strength, and protection. It is believed to provide a shield against negativity and harm, both physical and emotional. Its banded structure is thought to symbolize stability and a strong foundation, making it a stone for building lasting relationships and achieving personal goals. Sardonyx is also associated with clear communication and eloquence, helping the wearer to express themselves with confidence and integrity. It is often recommended for those in leadership positions or public-facing roles.
Mining and Global Sources
The geographical origins of these gemstones are as distinct as their appearances.
Peridot is mined in several locations around the world. Historically, the island of Zabargad in the Red Sea was the most significant source, and it continues to produce some gems. Today, the primary commercial sources include: * Pakistan: The San Bernardino area in the Pakistan-administered part of Kashmir is known for producing large, high-quality peridots. * United States: The San Carlos Apache Reservation in Arizona is a major source of peridot, producing gems of a often lighter, yellowish-green hue. * Other Sources: Peridot is also found in Australia, Brazil, China, Kenya, Mexico, Myanmar (Burma), Norway, South Africa, and Sri Lanka.
Sardonyx is a variety of chalcedony, which is a very common mineral found worldwide. It is not mined from a single, specific location but rather from any region where chalcedony deposits are found. Major sources include: * India: A primary source for commercially available sardonyx. * Brazil: Another significant producer of chalcedony, including banded varieties. * Germany * United States * Uruguay
Because chalcedony is so abundant, sardonyx is generally more affordable than many other gemstones, especially peridot of high quality.
Care and Cleaning
Proper care is essential to maintain the beauty and longevity of peridot and sardonyx jewelry. Both stones have a hardness of 6.5 to 7 on the Mohs scale, making them moderately durable but still susceptible to damage from harder stones and harsh chemicals.
Cleaning Peridot: * Use warm, soapy water and a soft brush (like a toothbrush) to gently clean the stone. * Avoid ultrasonic cleaners and steam cleaners, as the heat and vibrations can cause existing fractures to worsen. * Peridot is sensitive to rapid temperature changes, so it should not be exposed to extreme heat. * Store peridot jewelry separately from other gems to prevent scratches.
Cleaning Sardonyx: * Sardonyx can be cleaned with warm, soapy water and a soft cloth or brush. * It is generally safe for ultrasonic cleaners, but it is always best to check with a professional jeweler if the piece contains any other materials (like glue or other stones). * Avoid harsh chemicals and cosmetics, which can dull the stone's luster over time. * Like peridot, it should be stored in a soft pouch or separate compartment in a jewelry box to protect its polished surface.
Conclusion
The birthstones for August 23, peridot and sardonyx, offer a compelling study in contrasts. Peridot, the vibrant green gem from the Earth's mantle and the depths of space, represents the fiery energy of summer and the power of light. Sardonyx, the ancient banded stone of Roman warriors and artisans, symbolizes stability, courage, and clear communication.
Whether one is drawn to the brilliant glow of peridot or the layered history of sardonyx, both stones provide a tangible connection to the natural world and the rich tapestry of human culture. They are more than mere adornments; they are geological marvels and historical artifacts, carrying with them centuries of lore and symbolism. For those born on August 23, these gemstones offer a perfect blend of beauty, durability, and profound meaning, serving as enduring symbols of their birth month.