August is a month of vibrant summer energy, and its birthstones reflect this dynamic spirit. Unlike most months with a single designated gem, August boasts three official birthstones: peridot, spinel, and sardonyx. This unique trio offers a remarkable spectrum of colors, from the radiant green of peridot to the fiery reds of spinel and the earthy bands of sardonyx. Each stone possesses its own distinct geological origin, gemological profile, and rich tapestry of symbolism. For those born in August, or for anyone captivated by these gems, the choice is not merely aesthetic but also deeply personal, connecting the wearer to a legacy of natural wonder and cultural meaning. This article delves into the history, properties, and lore of peridot, spinel, and sardonyx, providing a comprehensive guide to the celebrated birthstones of August.
History and Lore
The historical journey of August's birthstones is as varied as the stones themselves, with traditions evolving over centuries. Sardonyx, the most ancient of the three, has been prized for millennia. As a form of onyx, it has long been associated with strength and protection. Its name derives from the Greek terms for "sard" (a reddish-brown chalcedony) and "onyx" (a black or banded variety), referencing its characteristic layered appearance. Historically, sardonyx was frequently used for cameos and intaglios, where its contrasting bands provided a perfect canvas for carved figures. It was believed to bestow courage and stability upon its wearer, making it a favored stone for seals and amulets.
Peridot’s history is shrouded in a degree of antiquity and confusion. Often mistaken for emeralls throughout history, peridot is believed to have adorned some of the most famous jewels of antiquity, including the purported "Topaz" of Cleopatra. The gem’s name is thought to have originated from the Arabic word "faridat," meaning "gem," though the exact etymology is unclear. For centuries, peridot was mined on the island of Zabargad (St. John’s Island) in the Red Sea, a source that supplied the gem to ancient Egyptian and Roman civilizations. Its luminous green was associated with the sun and was believed to possess healing powers, warding off evil spirits and bringing joy.
Spinel’s history is perhaps the most dramatic, marked by centuries of misidentification. For a long time, magnificent red spinels were mistaken for rubies. The most famous example is the "Black Prince’s Ruby," a massive red spinel that has been part of the British Crown Jewels since the 14th century. Similarly, the Timur Ruby, another large red spinel, was thought to be a ruby for much of its history. This confusion was not a reflection of spinel’s value but rather a testament to its stunning beauty. It was only in the 18th century that spinel was formally distinguished from ruby as a separate mineral species. Despite this, spinel has been prized in its own right, particularly in Asian and European courts, for its rich colors and exceptional durability.
The modern recognition of these stones as birthstones is more recent. The American Gem Trade Association (AGTA) and Jewelers of America (JA) have standardized the list. Peridot has been the official August birthstone since 1912. Sardonyx is recognized as the traditional birthstone. In 2016, spinel was added to the list, providing August-born individuals with a modern alternative that offers a wide array of colors. This expansion reflects a desire to offer more variety in color, affordability, and availability to consumers.
Geological Formation and Sources
The origins of these three gems are as diverse as their appearances, stemming from distinct geological processes and locations around the world.
Peridot is the gemological variety of the mineral olivine, a common silicate found in the Earth’s mantle. Its formation is unique, as it is one of the few gemstones found in igneous rocks, specifically in basalt and peridotite. Peridot can also be found in meteorites, adding to its otherworldly mystique. Major sources include Pakistan, Myanmar, China, India, and the United States. Notably, Hawaii’s volcanic islands, particularly the island of Oahu, are known for peridot grains washed ashore by volcanic activity. The gem’s color is directly tied to its iron content; ferrous iron (FeO) creates the green hue, while ferric iron (Fe2O3) contributes to more yellowish shades. The most valued peridot displays a rich, vibrant olive green with minimal brown undertones.
Spinel is a magnesium aluminum oxide with the chemical formula MgAl₂O₄. It forms in metamorphic rocks, often in contact with limestone or dolomite, and can also be found in alluvial deposits. Historically, the most significant source of red spinel was the Badakhshan region of Afghanistan, which supplied the gem to Asia and Europe for centuries. Today, major sources include Myanmar (Burma), which is renowned for producing some of the finest red and pink spinels, as well as Sri Lanka, Vietnam, and Tajikistan. The gem’s color spectrum is vast due to trace elements like chromium (for red) and iron (for blue and black hues). The most prized spinel is a vivid, saturated red, often compared to ruby.
Sardonyx is a banded variety of chalcedony, which is a microcrystalline form of quartz (silicon dioxide, SiO₂). It is composed of alternating layers of sard (a reddish-brown chalcedony) and onyx (typically black or dark brown). This banding is a result of the silica depositing in layers, often within volcanic rock cavities. While sardonyx is found in various locations, including Germany, India, and the United States, one of the most notable historical sources was the island of Sicily. The stone’s formation requires specific conditions where layers of different-colored chalcedony can precipitate sequentially, creating the distinctive patterns that make each piece unique.
Gemological Properties
Understanding the physical and optical characteristics of these gems is essential for identification, valuation, and care. The following table summarizes key gemological data for each stone, based on the provided sources.
| Gemstone | Mineral Group | Chemical Composition | Mohs Hardness | Key Color Characteristics |
|---|---|---|---|---|
| Peridot | Olivine | (Mg, Fe)₂SiO₄ | 6.5 – 7 | Ranges from yellow-green to olive to brown-green. Color comes from iron content. |
| Spinel | Spinel | MgAl₂O₄ | 8 | Available in a wide range: vivid red (most prized), pink, orange, purple, blue, black. |
| Sardonyx | Chalcedony (Quartz) | SiO₂ | 7 | Banded pattern of red, brown, white, and orange layers. |
Peridot is characterized by its consistent green color, which is unique among gemstones as it is not caused by trace impurities but by its fundamental chemical composition. It is a "day and night" stone, maintaining its color under various light sources, which has earned it the nickname "Evening Emerald." With a Mohs hardness of 6.5 to 7, it is durable enough for most jewelry but can be prone to scratching and requires careful handling. It has no cleavage, but its toughness is fair.
Spinel boasts an impressive Mohs hardness of 8, making it exceptionally durable and resistant to scratching, ideal for daily-wear jewelry. Its transparency can range from transparent to translucent, and it often contains inclusions. The most valuable spinel is transparent with a vivid, saturated color. Its refractive index is relatively high, contributing to its brilliance. The variety of colors available makes it a versatile gem for designers.
Sardonyx, as a member of the quartz family, has a Mohs hardness of 7, making it quite durable. Its defining feature is its banding, which is a result of its layered structure. It is typically cut en cabochon to showcase these patterns, though it can also be carved. Sardonyx is often used in cameos and intaglios due to its suitability for carving and the contrast between its layers. It is generally opaque to translucent.
Symbolism and Metaphysical Beliefs
Beyond their physical beauty, each of the August birthstones carries a legacy of symbolic meaning and metaphysical belief, often tied to their color and historical use.
Peridot is widely associated with positive energy. Sources describe it as a stone of joy, abundance, and emotional clarity. Its vibrant green hue is linked to the heart chakra, symbolizing healing and the release of negative patterns. It is believed to foster confidence and attract prosperity, making it a popular choice for those seeking to enhance their personal growth and well-being. In some traditions, it is also seen as a protective stone that wards off nightmares and negative energies.
Spinel is celebrated for its revitalizing properties. It symbolizes renewal, energy, and resilience. Different colors of spinel may carry specific meanings; for instance, red spinel is associated with passion and vitality, while blue spinel is linked to calm and clarity. It is often used as a stone of inspiration, helping to overcome lethargy and encouraging a positive outlook. Its historical connection to royalty adds a layer of nobility and strength to its symbolism.
Sardonyx is the stone of strength and stability. Its layered bands are seen as a representation of fortified foundations and enduring courage. Traditionally, it was believed to provide protection, particularly for soldiers and those in positions of authority. It is also associated with stable relationships and steadfastness, making it a meaningful gift for partners or a personal talisman for perseverance. Its earthy tones connect it to the grounding energies of the planet.
Care and Cleaning
Proper care is crucial to maintaining the beauty and longevity of these gemstones. Their differing hardness and structural properties dictate specific cleaning and handling guidelines.
Peridot, with a hardness of 6.5 to 7, requires careful handling to avoid scratches and abrasions. It should be cleaned using warm, soapy water and a soft brush. Avoid ultrasonic cleaners and steam cleaning, as the gem can be sensitive to sudden temperature changes and vibrations. Store peridot jewelry separately to prevent it from being scratched by harder gems or metals.
Spinel is relatively easy to care for due to its high hardness of 8. It can withstand ultrasonic cleaning and steam cleaning, but it is always best to check for any fractures or inclusions first. Warm, soapy water and a soft brush are safe for daily cleaning. Its durability makes it an excellent choice for rings and bracelets that see frequent wear.
Sardonyx, being a form of quartz, is also quite durable (hardness 7). It can be cleaned with warm, soapy water and a soft cloth. Ultrasonic cleaners are generally safe, but caution is advised if the stone has been dyed or treated, as vibrations might affect the treatment. It is also advisable to avoid harsh chemicals and prolonged exposure to intense heat, which could damage the stone or its settings.
Conclusion
The August birthstones—peridot, spinel, and sardonyx—offer a remarkable trio that caters to a wide range of tastes and preferences. From the radiant, joyful green of peridot to the resilient, fiery spectrum of spinel and the grounded, protective bands of sardonyx, each stone provides a unique connection to the earth's geological processes and human history. Their journey from ancient amulets and royal crowns to modern jewelry reflects their enduring appeal. For those born in August, this trio provides not just a birthstone, but a choice of gem that can symbolize personal attributes, from confidence and abundance to strength and inspiration. Understanding their origins, properties, and meanings allows for a deeper appreciation of these natural treasures, ensuring that the light and energy they embody can be cherished for generations.