August stands as a unique month in the gemological calendar, boasting not one, but three officially recognized birthstones. While the vivid green of Peridot often claims the spotlight as the traditional and primary gem for this summer month, the alternatives—Spinel and Sardonyx—offer distinct histories, aesthetic qualities, and symbolic meanings that are equally compelling. For those born in August, or for jewelry enthusiasts seeking to understand the full spectrum of options, these stones represent a rich tapestry of geological wonder and cultural significance.
The modern list of August birthstones reflects a blend of ancient tradition and contemporary discovery. Peridot, with its singular formation process and uplifting hue, has been cherished for millennia. Spinel, long mistaken for other precious gems, has recently been elevated to official status, celebrated for its dazzling array of colors and durability. Sardonyx, an ancient variety of onyx, offers a bold, earthy contrast with its distinctive banding. Together, they provide a versatile palette for personal expression, from the classic elegance of a green gem to the fiery brilliance of a red spinel or the stoic beauty of a layered sardonyx. This article explores the geological origins, gemological properties, historical lore, and practical care of these three magnificent stones, drawing upon established knowledge to guide collectors and buyers.
Peridot: The Gem of the Sun
Peridot is the singular primary birthstone for August, a gem celebrated for its distinctive olive-to-lime green hue. Unlike many other gemstones, which derive their color from trace impurities, Peridot’s color is an intrinsic part of its chemical composition. This gem belongs to the olivine mineral group, a silicate of magnesium and iron. Its signature green glow is caused by the presence of iron, and the intensity of the color can vary depending on the amount of iron present in the crystal structure.
Geological Formation and Sources
Peridot’s formation process is as unique as its color. It is one of the few gemstones formed in the Earth’s mantle, brought to the surface by volcanic activity. This deep-earth origin distinguishes it from gems that crystallize in the crust. The gem can also be found in pallasite meteorites, offering a truly extraterrestrial connection. Historically, the island of Zabargad in the Red Sea was a primary source of high-quality Peridot, mined for over 3,500 years.
Today, significant sources of Peridot include Pakistan, which produces some of the finest crystals with exceptional clarity and color; Myanmar (Burma); China; and the United States, particularly Arizona. The San Carlos Apache Reservation in Arizona is a notable source, producing Peridot in a range of green shades, often found in lava fields. The town near this mine is even named Peridot, underscoring the gem's importance to the region.
Gemological Properties
Peridot possesses a hardness of 6.5 to 7 on the Mohs scale, making it suitable for jewelry that is worn with moderate care, such as earrings and pendants. While it can be used in rings, it is more susceptible to scratching than harder gems like sapphire or diamond. It has no cleavage, meaning it does not have natural planes of weakness where it might split, but it does have a conchoidal fracture. Its refractive index is relatively low for a colored stone, contributing to its soft, glowing appearance rather than a sharp, mirror-like brilliance.
History and Lore
The history of Peridot is steeped in legend. The ancient Egyptians called it the "gem of the sun," believing it offered protection against evil spirits and nightmares. It was mined on the island of Zabargad as early as 1500 B.C. and was used in the treasures of the Egyptian priesthood and pharaohs. Some historians believe that Cleopatra’s famous emerald collection may have actually been Peridot.
In medieval times, Peridot was used to craft chalices and church ornaments, and it was believed to be the "Evening Emerald" because its green color remained visible even under candlelight. Its lore is consistently associated with light, positivity, and healing. It is believed to bring good fortune, peace, and success, and is often associated with the heart chakra, promoting emotional balance and openness.
Symbolism and Metaphysical Beliefs
Metaphysically, Peridot is known as a stone of compassion and renewal. It is said to heal hurt feelings, bring about personal growth, and inspire openness to new experiences. Its connection to the sun gives it an energizing quality, dispelling lethargy and encouraging action. For August-born individuals, it is thought to enhance confidence and clarity, aligning with the astrological signs of Leo and Virgo.
Spinel: The Revitalized Gem
For many centuries, Spinel was an unsung hero of the gem world, often confused with more famous stones like ruby and sapphire. It was only in 2016 that the American Gem Trade Association (AGTA) officially added Spinel as a modern birthstone for August, recognizing its beauty, durability, and distinct identity.
Geological Formation and Sources
Spinel is a magnesium aluminum oxide, crystallizing in the cubic system. It forms under high-temperature, low-pressure conditions, often in metamorphic rocks like marble and alluvial deposits. Major sources of Spinel include Myanmar (Burma), which is famous for its vibrant red "ruby" spinels; Sri Lanka; Vietnam; and Tajikistan. The gem’s ability to form in a wide range of colors is due to trace elements like iron, chromium, and cobalt.
Gemological Properties
Spinel is an exceptionally durable gem, 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 will see daily wear. It has a refractive index similar to that of sapphire but lacks the dichroism (showing two different colors when viewed from different angles) characteristic of corundum. Its most remarkable feature is its color range. While red is the most prized, Spinel appears in a stunning spectrum: blue, pink, purple, black, orange, and even colorless varieties.
History and Lore
Spinel’s history is a story of mistaken identity. The "Black Prince’s Ruby" in the British Imperial State Crown is a massive red Spinel, as is the "Timur Ruby." For centuries, these magnificent stones were believed to be rubies. This confusion, however, does not diminish Spinel’s own legacy. In ancient times, Spinel was believed to protect against sadness and promote vitality.
The recent designation as an August birthstone has brought Spinel to the forefront of the gem market. It is now appreciated for its own unique qualities: its brilliance, its range of colors, and its affordability compared to ruby and sapphire.
Symbolism and Metaphysical Beliefs
Spinel is often associated with revitalization and energy. It is believed to remove obstacles, clear negative energy, and encourage the flow of creative ideas. Red and pink spinels are linked to passion and love, while blue spinels are associated with calm and clarity. Some sources also attribute healing properties to Spinel, suggesting it can aid in physical recovery and boost the body’s natural healing processes.
Sardonyx: The Ancient Stone of Strength
Sardonyx is the third birthstone for August, a variety of onyx characterized by its distinctive layers of sard (a reddish-brown chalcedony) and onyx (banded chalcedony). Its appearance is marked by alternating bands of light and dark colors, often in shades of brown, black, and white.
Geological Formation and Sources
Sardonyx is a cryptocrystalline form of quartz, composed of silicon dioxide. It forms in volcanic rock cavities, where silica-rich fluids deposit layers of chalcedony over time. The banding effect is created by variations in the iron oxide impurities that color the layers. Sources for Sardonyx are widespread and include India, Brazil, Germany, and the United States.
Gemological Properties
With a hardness of 6.5 to 7 on the Mohs scale, Sardonyx is durable enough for everyday wear, though it requires care to avoid scratches. It has a waxy luster and is typically opaque. Unlike many other gems, its value lies not in transparency or brilliance, but in the sharpness and contrast of its bands. The most prized Sardonyx features clear, distinct bands of alternating colors.
History and Lore
Sardonyx is perhaps the most historically significant of the three August stones. It was a favorite gem in ancient Rome and Greece, where it was used extensively for cameos and intaglios. Its name is derived from the Greek words "sard" (reddish-brown) and "onyx" (veined gem). In ancient times, Sardonyx was a stone of strength and protection. Warriors wore it into battle, believing it would grant them courage and shield them from harm. It was also used in signet rings, as wax did not stick to its surface, making it ideal for sealing documents.
Symbolism and Metaphysical Beliefs
Sardonyx is traditionally associated with courage, confidence, and stability. It is believed to promote discipline and steadfastness, making it a popular talisman for public speakers and performers. In metaphysical practices, Sardonyx is thought to enhance willpower and integrity, helping the wearer to maintain a strong moral compass. It is also linked to happiness and good fortune in marriage, often used as a wedding anniversary gift.
Care and Cleaning
Proper care is essential to maintain the beauty of these gemstones over time. Due to their varying hardness and chemical composition, each requires specific handling.
Peridot Care
Peridot, with a hardness of 6.5 to 7, should be protected from hard knocks and abrasive materials. It is sensitive to rapid temperature changes, which can cause fracturing. To clean Peridot, use warm, soapy water and a soft brush. Avoid ultrasonic cleaners and steam cleaning, as the heat and vibrations can damage the stone. Store it separately from harder gems to prevent scratching.
Spinel Care
Spinel is one of the more durable gemstones, ranking an 8 on the Mohs scale. It is resistant to scratching and is generally stable when exposed to light and heat. Spinel can be safely cleaned using warm soapy water, an ultrasonic cleaner, or a steam cleaner. However, it is always wise to inspect the stone for any fractures or inclusions before using intense cleaning methods.
Sardonyx Care
As a variety of quartz, Sardonyx has a hardness of 6.5 to 7. It is relatively tough but can be scratched by harder materials. Cleaning is straightforward: use warm, soapy water and a soft brush. Ultrasonic cleaners are generally safe, but steam cleaning is not recommended due to the potential for thermal shock, especially if the stone has been fracture-filled. Avoid harsh chemicals and sudden temperature changes.
Conclusion
The birthstones of August—Peridot, Spinel, and Sardonyx—offer a compelling trio of options that cater to a wide range of tastes and preferences. From the luminous, sun-kissed green of Peridot to the dazzling versatility of Spinel and the bold, historical banding of Sardonyx, each stone tells a unique story. They represent a confluence of geological marvels, ancient human history, and enduring symbolic power. For the August-born individual, these gems provide a personal connection to the earth's depths and the rich cultural heritage of gemology. Whether chosen for their beauty, durability, or lore, these stones remain timeless symbols of summer's vibrant energy.