The month of August is uniquely distinguished in the world of gemology by possessing three official birthstones: peridot, spinel, and sardonyx. This triad offers a remarkable spectrum of color, history, and origin, ranging from the vibrant greens of volcanic depths to the fiery reds of metamorphic environments and the banded elegance of ancient chalcedony. While peridot is often recognized for its singular lime-green hue, the inclusion of spinel and sardonyx provides a diverse palette that appeals to a wide array of tastes and preferences. These stones are not merely decorative; they are deeply rooted in human history, associated with virtues of strength, protection, and healing.
The journey of August’s birthstones through time reveals a fascinating evolution. Sardonyx stands as the original August gem, with a history spanning over four millennia, serving as a talisman for warriors and a symbol of marital happiness. Peridot, often mistaken for emerald throughout antiquity, carries the lore of the "gem of the sun" and possesses the extraordinary distinction of being found in both the Earth's mantle and extraterrestrial meteorites. Spinel, long overshadowed by its resemblance to ruby, has recently claimed its own identity as a precious gem in its own right, celebrated for its exceptional hardness and vivid colors.
This article explores the geological formation, gemological properties, historical lore, and cultural significance of these three captivating stones. By examining the scientific characteristics and the ancient beliefs associated with them, we gain a deeper appreciation for the enduring appeal of August’s birthstones.
Peridot: The Gem of the Sun
Peridot, the gem-quality variety of the mineral olivine, is the most recognized birthstone for August. It is celebrated for its distinct color range, which varies from yellow-green to deep olive, with the most highly valued stones exhibiting a rich, lime-green hue. The name "peridot" is derived from the Arabic word faridat, meaning "gem." Unlike many gemstones that require treatments to enhance their color, peridot’s natural brightness is often pristine, making it a favorite among collectors and enthusiasts who value natural gemstones.
Geological Formation and Sources
Peridot is formed under extreme geological conditions. It is primarily found in the hardened lava that carries it from deep within the Earth’s mantle, a process that brings the gem to the surface via volcanic activity. In a truly celestial occurrence, peridot has also been identified in meteorites that traveled from outer space, leading to its nickname as the "space gem." This extraterrestrial connection is noted in sources mentioning its presence on the Moon and in meteorites. Most commercial peridot today is sourced from Arizona, Pakistan, and China.
History and Lore
The history of peridot is rich and often confused with other green gemstones, such as emerald and topaz. Historians speculate that Cleopatra’s famous collection of emeralds may actually have been peridot. The Shrine of the Three Holy Kings in Germany’s Cologne Cathedral is decorated with 200 carats of gems long believed to be emeralds, which are now identified as peridot.
Ancient cultures held the stone in high regard. The Egyptians referred to it as the "gem of the sun," believing it was brought to Earth from an "exploding sun." They mined the stone at night, believing it absorbed the sun's rays and released them in the dark. The Romans similarly admired its luminosity, calling it "the evening gem" and believing it glowed in the dark. In biblical times, it was known as chrysolite, derived from the Greek chrysolithos (golden stone). There is evidence suggesting it was used on the breastplate of Aaron. Folklore attributed protective qualities to peridot, believing it could ward off evil spirits and "terrors of the night." In Hawaiian culture, peridot is viewed as the tears of Pele, the Goddess of Elements.
Gemological Properties
Peridot is a relatively hard and durable gemstone, suitable for various types of jewelry. Its chemical composition is magnesium iron silicate (Mg,Fe)2SiO4. While the provided sources do not list a specific Mohs hardness for peridot, standard gemological knowledge (often cited as 6.5–7) aligns with its durability. However, based strictly on the provided texts, we must rely on the descriptions of its color and formation rather than specific hardness data for peridot.
Spinel: The Underappreciated Beauty
Spinel is the newest addition to the August birthstone family, having officially earned its place in 2016 alongside peridot and sardonyx. For centuries, spinel was underappreciated, often mistaken for ruby due to its brilliant red varieties. Today, it is recognized for its own distinct beauty and durability.
Etymology and Origins
The name "spinel" is believed to originate from the Latin spina, meaning "thorn," a reference to the pointed shape of its natural crystals. Spinel forms in the metamorphic rocks of Myanmar (Burma), Sri Lanka, Vietnam, and Tanzania. These regions are renowned for producing high-quality spinel crystals.
Gemological Properties
Spinel possesses excellent physical characteristics that make it ideal for jewelry. It belongs to the cubic crystal system and exhibits a wide range of colors, including red, pink, purple, blue, orange, and black.
Spinel Properties At Glance: * Color: Red, pink, purple, blue, orange, black * Mohs Hardness: 7.5–8 * Crystal System: Cubic * Common Sources: Myanmar (Burma), Sri Lanka, Vietnam, Tanzania
Historical Context
Spinel’s history is marked by confusion with ruby. The "Black Prince's Ruby" in the British Imperial State Crown is actually a large red spinel. It was not until recent years that spinel was properly distinguished from ruby and corundum. Its inclusion as a modern birthstone acknowledges its growing popularity among consumers seeking an alternative to ruby, offering similar visual appeal with greater affordability and distinct gemological properties.
Sardonyx: The Original August Birthstone
Sardonyx is the oldest of the three August birthstones, with a history dating back more than 4,000 years. It is a variety of chalcedony, a microcrystalline form of quartz, characterized by its distinctive banding.
Appearance and Formation
Sardonyx is a combination of "sard" (a reddish-brown variety of chalcedony) and "onyx" (a layered form of quartz). The resulting gem features bold bands of reddish-brown, white, and orange. This banded appearance makes it unique among the August stones. It forms in volcanic environments where silica-rich fluids deposit layers in rock fissures.
Historical Significance and Lore
Sardonyx has been used since ancient times in protective amulets and talismans. In ancient Egypt and Rome, it was highly valued. Roman soldiers would wear sardonyx engraved with images of heroes or gods to boost courage in battle. It was believed to attract stability, lasting happiness, and luck in love and marriage.
Christian theologians believed sardonyx represented the strength of spiritual life. It was considered an aid to protect the wearer from infectious diseases and the bites of venomous creatures, particularly scorpions. If hung around the neck, it was believed to attract friends and bring success in legal matters. The Swedish naturalist and mystic Swedenborg interpreted sardonyx as representing "Love of Good and Light."
Gemological Properties
Sardonyx is durable, though slightly softer than spinel. Its trigonal crystal system and banded structure define its identity.
Sardonyx Properties At Glance: * Color: Banded red, brown, white, and orange * Mohs Hardness: 6.5–7 * Crystal System: Trigonal (a variety of chalcedony) * Common Sources: India, Brazil, Germany, Uruguay, United States
Comparative Gemological Data
To provide a clear overview of the physical properties of the three August birthstones, the following table summarizes the data provided in the sources.
| Gemstone | Mohs Hardness | Crystal System | Primary Colors | Key Sources |
|---|---|---|---|---|
| Spinel | 7.5 – 8 | Cubic | Red, pink, purple, blue, orange, black | Myanmar, Sri Lanka, Vietnam, Tanzania |
| Sardonyx | 6.5 – 7 | Trigonal (Chalcedony) | Banded red, brown, white, orange | India, Brazil, Germany, Uruguay, USA |
| Peridot | Not specified in sources | Not specified in sources | Yellow-green to deep olive, lime-green | Arizona, Pakistan, China, Meteorites |
Note: While standard gemological texts list Peridot at 6.5–7, the provided sources focus on its color and origin without explicitly stating its hardness.
Symbolism and Metaphysical Beliefs
The symbolism attached to August’s birthstones is as varied as the stones themselves. Peridot is associated with prosperity, good fortune, and peace. Its ancient reputation as a protector against nightmares and evil spirits remains a significant part of its lore. The association with the sun and fire links it to vitality and power.
Spinel, while lacking the extensive ancient folklore of the other two, is associated with revitalization and renewed energy. Its modern status as a birthstone brings a contemporary sense of value and distinction, symbolizing the joy of finding something precious that was previously overlooked.
Sardonyx is the stone of strength and protection. Its association with marital happiness and stability makes it a meaningful gift for anniversaries or weddings. The belief that it attracts friends and success in legal matters speaks to its role as a stone of social and ethical integrity.
Care and Cleaning
Understanding the physical properties of these stones is essential for their care.
Spinel is the hardest of the trio (Mohs 7.5–8), making it highly resistant to scratching and suitable for daily wear. It can be cleaned with warm soapy water and a soft brush.
Sardonyx (Mohs 6.5–7) is durable but slightly softer than spinel. It is generally safe to clean with warm soapy water. Care should be taken to avoid hard impacts that could chip the bands or fracture the stone.
Peridot, while not assigned a hardness in the provided texts, is generally understood to be in the 6.5–7 range. It is moderately durable but can be susceptible to scratching if worn in rings exposed to hard surfaces. Cleaning with warm soapy water is recommended; however, ultrasonic cleaners should be avoided if the stone has inclusions, and steam cleaning is not recommended due to potential thermal shock.
Conclusion
The August birthstones—peridot, spinel, and sardonyx—offer a compelling narrative of geological wonder and human history. Peridot connects the wearer to the fiery depths of the Earth and the cold vastness of space, a "gem of the sun" with a luminous legacy. Spinel provides a modern alternative with ancient roots, dazzling with a hardness and color range that rivals the most precious gems. Sardonyx serves as a link to the earliest civilizations, a stone of warriors and lovers, defined by its sturdy and elegant bands.
Together, they represent strength, protection, and vitality. Whether chosen for their vibrant colors, their historical significance, or their metaphysical properties, these three stones ensure that anyone born in August has a gemstone that perfectly captures the spirit of their birth month. As the gemological community continues to uncover the secrets of these minerals, their value and appeal only continue to grow.