The month of August is uniquely represented by three distinct and historically significant birthstones: the vibrant peridot, the multifaceted spinel, and the ancient sardonyx. Each gemstone carries a rich tapestry of geological origins, cultural lore, and gemological properties, offering a diverse palette for those born in this summer month. While peridot is often celebrated as the primary birthstone for its singular green hue, spinel and sardonyx provide fascinating alternatives with their own deep histories. This article delves into the science, history, and symbolism of these three August birthstones, providing a thorough exploration for gemstone enthusiasts, collectors, and jewelry buyers.
The Primary Birthstone: Peridot
Peridot stands as the most recognized birthstone for August, celebrated for its distinctive olive-green color. This gem is not a product of impurities but is the gem variety of the mineral olivine, formed deep within the Earth’s mantle. Its formation under extreme conditions is a key part of its allure, as it can be brought to the surface through volcanic activity and is even found within meteorites that have traveled from outer space.
History and Lore
Peridot has been cherished for centuries, with a history often intertwined with other green gems. The word “peridot” is believed to derive from the Arabic faridat, meaning gem. Ancient civilizations valued it for its beauty and protective qualities, believing it could ward off evil spirits and bring good fortune. Its historical significance is highlighted by its presence in revered artifacts. For instance, the Shrine of the Three Holy Kings in Germany’s Cologne Cathedral is adorned with 200 carats of gems long mistaken for emeralds but later identified as peridot. Some historians even speculate that Cleopatra’s famed collection of emeralds may have actually contained peridot. The Red Sea island of Topazios, a source that gave its name to the gemstone topaz, was actually a source of peridot, leading to centuries of confusion between the two stones.
Geological Formation and Sources
Peridot’s formation is unique among gemstones. It is one of the few gems that occur in a single color family, though its shades can vary significantly. The color is determined by its iron and magnesium composition. Ferrous iron (FeO) is responsible for the green hue, while ferric iron (Fe2O3) contributes to more yellowish tones. This results in a color range from yellow-green and lime green to olive and brownish-green. Major sources of peridot include the lava fields of Hawaii, the mines of Kashmir, and significant deposits in India, China, Pakistan, Myanmar, and the United States. The Luc Yen region in Vietnam has also produced peridot, though it is more renowned for spinel.
Gemological Properties
Peridot is a relatively durable gem, making it suitable for various types of jewelry. Its hardness on the Mohs scale is between 6.5 and 7, which means it is resistant to scratching but can be prone to chipping if struck with force. Its chemical formula is (Mg, Fe)₂SiO₄. The gem is known for its "evening emerald" nickname because it maintains its vibrant color under artificial light, unlike many other green gems that can appear duller in non-natural lighting. The cut of a peridot significantly influences its perceived color and brilliance; a well-cut stone will enhance its lively green hue. Settings also play a role, with gold settings often enhancing the green tones and silver settings providing a more neutral backdrop.
Symbolism and Metaphysical Beliefs
Peridot is rich in symbolic meaning. It is traditionally associated with protection, healing, prosperity, and abundance. In modern times, it is seen as a stone of clarity and positive energy, often linked to the heart chakra for its ability to soothe and rejuvenate. Its connection to the sun and fire elements, particularly for the zodiac sign Leo, aligns it with warmth, confidence, and vitality.
Care and Cleaning
Caring for peridot requires attention due to its moderate hardness. It is safe to clean with warm, soapy water and a soft brush. Ultrasonic cleaners are generally not recommended, especially if the stone has any fractures, as the vibrations could cause damage. Steam cleaning should also be avoided. To prevent scratches, store peridot jewelry separately from harder gems like diamonds or sapphires.
The Underappreciated Alternative: Spinel
For centuries, red spinel was mistaken for ruby, a testament to its stunning beauty and durability. It was only in the 18th century that spinel was recognized as a distinct mineral. Today, it is rightfully celebrated as a modern birthstone for August, offering a brilliant array of colors that make it a versatile and attractive choice.
History and Lore
Spinel’s history is one of mistaken identity and rediscovery. The most famous example is the Black Prince’s Ruby in the British Imperial State Crown, which is actually a large red spinel. For centuries, spinel was underappreciated, but modern consumers seeking an alternative to the often-prohibitive cost of ruby have turned to spinel for its similar appearance and excellent properties. Its name is thought to come from the Greek word spinthos, meaning spark, a fitting description for its brilliant luster.
Geological Formation and Sources
Spinel forms in metamorphic rocks and in alluvial deposits. It is found in a spectacular variety of colors, including red, pink, blue, purple, and violet-blue. Key sources include: - Myanmar (Burma): Historically the most famous source for red spinel. - Vietnam: The Luc Yen region has produced deep red, purple, pink, violet, and violet-blue spinel since the 1980s, with vivid blue stones discovered in the 2000s. - Tanzania: A 2007 discovery yielded captivating pinkish and orangy-red spinel, as well as purple and blue varieties. - Sri Lanka, Tajikistan, and Afghanistan are also notable sources.
Gemological Properties
Spinel is a highly durable gem, ranking 8 on the Mohs scale of hardness, making it exceptionally suitable for rings and daily-wear jewelry. Its chemical formula is MgAl₂O₄. Spinel is stable when exposed to light and most chemicals, which contributes to its longevity in jewelry. However, high heat can cause some colors to fade, so care should be taken with heat treatments. Its refractive index and specific gravity place it in a distinct category from ruby and sapphire, which is how gemologists differentiate it.
Symbolism and Metaphysical Beliefs
Spinel is associated with revitalizing energy, renewal, and protection. It is believed to inspire passion and courage, especially in its red forms, while its other colors are linked to calm, clarity, and balance. As a birthstone for August, it is said to bring prosperity and vitality to those born in the month.
Care and Cleaning
Spinel’s hardness makes it relatively easy to care for. Ultrasonic and steam cleaners are typically safe, but if the stone has any fractures, warm soapy water with a soft brush is the safest cleaning method. It is important to avoid extreme temperature changes and harsh chemicals to maintain the stone’s color and integrity.
The Ancient Original: Sardonyx
Sardonyx holds the distinction of being the original birthstone for August, with a history dating back over 4,000 years. It is not a single mineral but a banded variety of chalcedony, a cryptocrystalline form of quartz.
History and Lore
Sardonyx was immensely popular in ancient Rome and Greece, primarily for use in seals and signet rings. Its smooth, waxy surface prevented hot wax from sticking, making it ideal for imprinting signatures. The stone was also valued for its perceived protective qualities. As a birthstone, it represents longevity, happiness, and marital bliss. Its layered bands of color—typically brownish-red sard alternating with black or white onyx—were believed to create a powerful talisman.
Geological Formation and Sources
Sardonyx forms when bands of sard (a reddish-brown chalcedony) and onyx (a banded chalcedony with black and white layers) are deposited in alternating layers within cavities of volcanic rock. This process creates the distinctive striped appearance. Sources of sardonyx are not as prominently detailed in the provided materials, but chalcedony deposits are found worldwide, including in India, Brazil, Uruguay, and the United States.
Gemological Properties
As a member of the quartz family, sardonyx has a hardness of 7 on the Mohs scale, making it durable for jewelry. Its chemical composition is silicon dioxide (SiO₂). The bands of color are its most defining feature, and skilled artisans often cut the stone to highlight these patterns. Sardonyx can be carved into cameos and intaglios, a tradition that continues today.
Symbolism and Metaphysical Beliefs
Sardonyx is traditionally associated with strength, protection, and courage. It is believed to enhance willpower and discipline. In ancient times, it was worn to ward off evil and attract good fortune. As a birthstone, it symbolizes a strong foundation and enduring happiness.
Care and Cleaning
Caring for sardonyx is straightforward due to its quartz nature. It can be cleaned with warm, soapy water and a soft cloth. Avoid harsh chemicals and ultrasonic cleaners if the stone is carved or has any inclusions, as vibrations could damage it. Store it separately from harder gems to prevent scratching.
Comparative Gemological Properties
The three August birthstones differ significantly in their physical and chemical properties, which influences their use in jewelry and care requirements. The following table summarizes key gemological data derived from the provided sources.
| Gemstone | Mineral Group | Chemical Formula | Mohs Hardness | Color Range | Key Sources |
|---|---|---|---|---|---|
| Peridot | Olivine | (Mg, Fe)₂SiO₄ | 6.5 – 7 | Yellow-green, olive, brownish-green | USA, Pakistan, Myanmar, China, India, Hawaii |
| Spinel | Spinel | MgAl₂O₄ | 8 | Red, pink, blue, purple, violet-blue | Myanmar, Vietnam, Tanzania, Sri Lanka |
| Sardonyx | Chalcedony (Quartz) | SiO₂ | 7 | Bands of brownish-red, white, black | Various global deposits for chalcedony |
Conclusion
The August birthstones—peridot, spinel, and sardonyx—offer a remarkable journey through geological wonder, human history, and symbolic meaning. Peridot, with its mantle-born green fire, captivates with its singular color and ancient protective lore. Spinel, once mistaken for ruby, dazzles with its durability and vibrant spectrum of colors, embodying revitalization and passion. Sardonyx, the original August stone, connects the modern wearer to millennia of tradition through its banded elegance and associations with strength and longevity. Together, they provide August-born individuals with a rich selection of gems, each with a unique story to tell and a distinct beauty to adorn. Whether chosen for its color, historical significance, or metaphysical properties, any of these three stones makes for a profound and personal connection to the month of August.