For those born in August and those who seek its signature gemstones in jewelry, the selection is unparalleled in both diversity and beauty. The month of August is uniquely distinguished by not one, but three birthstones: peridot, spinel, and sardonyx. Each of these gems carries a rich tapestry of geological heritage, historical significance, and symbolic meaning. Whether the subject is the vivid greens of peridot, the fiery reds and purples of spinel, or the banded elegance of sardonyx, August’s birthstones embody a striking array of colors and characteristics that reflect their varied origins and storied pasts.
This article delves deeply into the gemological attributes, historical narratives, and cultural symbolism of August’s trio of birthstones. By examining how each stone was formed, where it is found, and how it has been valued across centuries, this exploration provides a comprehensive view of why these gemstones remain popular among gem enthusiasts and jewelry connoisseurs alike.
History and Lore
Sardonyx: The Ancient August Birthstone
As the original birthstone of August, sardonyx boasts an ancient lineage stretching over 4,000 years. This gem is a combination of two forms of chalcedony, which is a type of cryptocrystalline quartz. Its characteristic appearance—alternating bands of brownish red to dark orange (sard) and white or black (onyx)—has made it a favored material for cameos, intaglios, and seals since the Roman era. In fact, sardonyx held such practical value that Roman seals were often crafted from it because hot wax would not adhere to its surface, making it ideal for use with wax seals in documents and correspondence.
The enduring appeal of sardonyx lies in its durability and ease of carving. Though it is softer and more porous than many modern gemstones, its historical use in intricate carvings attests to its utility and longevity. The stone has also been attributed with metaphysical properties, including the ability to ward off evil and inspire courage.
Peridot: From the Sun to the Lava
Peridot, known for its eye-catching yellowish green to greenish yellow hues, is the olivine mineral variety most commonly recognized as the primary August birthstone today. Its name has an uncertain origin, but peridot has been mistakenly called topaz and emerald in the past, due to its color similarities. A notable example is the collection in the Shrine of the Three Holy Kings in Cologne Cathedral, where 200 carats of gems originally believed to be emeralds were later identified as peridot.
Peridot's history is interwoven with myth and belief. The ancient Egyptians referred to peridot as the “gem of the Sun,” associating it with the healing properties of sunlight. It was even thought to ward off nighttime evil spirits, a belief that persisted through various cultures and time periods. Given its cosmic origins—being found in meteorites and volcanic lava—some cultures have also attributed to peridot a stellar or divine heritage.
Spinel: The Misunderstood Gem
Of the three, spinel is perhaps the most dramatic in both appearance and history. Known for its diverse color palette, including intense red, vibrant pink, orange, purple, blue, and violet, spinel was frequently mistaken for ruby and sapphire. Notably, the Black Prince’s “ruby”, a 170-carat gem set in Great Britain’s Imperial State Crown, is in fact a red spinel. This misinterpretation persisted until the 18th century, when the chemical and mineralogical distinctions between spinel and ruby were finally recognized.
Spinel was also attributed with healing powers, particularly in red hues, where it was believed to assist with blood loss and inflammatory conditions. Red spinel was used as a remedy and was also thought to promote emotional harmony. It is also associated with the 22nd wedding anniversary, and thus holds a significant place in both jewelry traditions and romantic symbolism.
Geological Formation and Sources
Peridot: A Stone Formed in Extreme Conditions
Peridot is the gem variety of olivine, formed under intense heat and pressure deep within the Earth’s mantle or carried to the surface via volcanic activity. It can also be found in meteorites, an extraterrestrial origin that adds to its scientific and cultural allure. The color of peridot is derived from the presence of iron (Fe) in its structure; higher iron content yields deeper greens, while lower iron gives lighter, yellowish greens.
Peridot is typically found in volcanic rocks, and its occurrence in lavas flows in places like Hawaii has captured public interest. It is also mined in locations such as:
- Zabargad (St. John's Island) in the Red Sea
- Arizona and Hawaii in the United States
- Maui and the Canary Islands
- Australia, India, and several African nations
The Red Sea island of Topazios, which is historically tied to the name “topaz,” was once a significant source of peridot, further highlighting the gem's entanglement with linguistic and cultural misinterpretations.
Spinel: A Kaleidoscope of Color from Around the World
Spinel is a refractive and colorful crystal, belonging to the oxide mineral class, and is composed of magnesium aluminum oxide (MgAl₂O₄). Its wide color variety is due to chromophores—elements such as chromium, iron, and cobalt—that influence the gem's hue. Notably, red spinel most often derives its color from chromium, the same element that also imparts color to rubies.
Until recently, spinel was largely underappreciated, partially due to its frequent misclassification as ruby or sapphire. However, with the 2007 discovery in Tanzania of vivid pink and orangy red spinels, there has been a surge in popularity and demand from collectors and jewelers.
Major spinel sources include:
- Tajikistan – Known for brilliant red and violet-blue spinels
- Myanmar – Famous for hot pink and red spinels
- Sri Lanka and Vietnam – Provide blue and violet tones
- Pakistan and Tanzania – Yield a diverse array of colors
These geographic distributions underscore not only spinel's aesthetic versatility but also its global significance in gem trade history.
Sardonyx: A Banded Beauty from the Earth
Sardonyx is a banded chalcedony, formed through the slow deposition of silica in cavities of volcanic rocks, over millennia. The process of banding occurs naturally due to variations in mineral content in the water that fills the cavities where the stone forms. The color bands arise from iron and other impurities present in the water or sediment.
Historically, sardonyx was mined in ancient Rome, with Armenia and the Caucasus region being key sources. Over time, significant deposits have been found in:
- Brazil
- India
- Indonesia
- Uruguay
Sardonyx remains a popular choice for cameos, engraved seals, and jewelry settings, especially due to its durability and vibrant color contrast.
Gemological Properties
Peridot: The Cosmic Green Gem
Peridot is known for its transparency, vibrant color, and relatively high refractive index (about 1.65 to 1.69). Here are the key gemological properties of peridot:
| Property | Value |
|---|---|
| Chemical Formula | (Mg, Fe)₂SiO₄ |
| Crystal System | Orthorhombic |
| Hardness (Mohs Scale) | 6.5 – 7 |
| Refractive Index | 1.654 – 1.690 |
| Specific Gravity | 3.3 – 4.4 |
| Cleavage | Perfect cleavage in two directions |
| Fracture | Conchoidal |
| Inclusions | Commonly contains small inclusions |
Peridot’s cleavage makes it more susceptible to chipping, especially in rings or bracelets, so proper setting and regular inspection are important for jewelry maintenance.
Although peridot can be found in a range of green-to-yellowish greens, true gem quality is associated only with the yellowish green to greenish yellow tone. The stronger the green tone and the higher the clarity, the more valuable the gem.
Spinel: The Misunderstood Marvel
Spinel is admired for its excellent clarity, high luster, and brilliance—qualities that make it comparable to ruby and sapphire in performance, even with softer structure. Here are the key gemological characteristics of spinel:
| Property | Value |
|---|---|
| Chemical Formula | MgAl₂O₄ |
| Crystal System | Cubic |
| Hardness (Mohs Scale) | 8 |
| Refractive Index | 1.718 – 1.723 |
| Specific Gravity | 3.6 – 4.0 |
| Cleavage | None (can have fractures but not cleavage) |
| Fracture | Conchoidal |
| Inclusions | Rare, but visible inclusions are common in rough stones |
| Color Zoning | Not typically zoned |
Spinel’s cubic crystal structure contributes to its uniform luster, while its relatively high refractive index gives it a sparkling, glass-like appearance. The red and pink hues, in particular, are highly prized, with certain colors commanding prices surpassing those of rubies.
Spinel’s hardness (8 on the Mohs scale) makes it suitable for daily wear, particularly in rings and bracelets, and its lack of cleavage means that it is less prone to chipping than peridot.
Sardonyx: The Layered Stone of Strength
As a variety of chalcedony, sardonyx is particularly favored for its bands and durability. Here are its primary gemological properties:
| Property | Value |
|---|---|
| Chemical Formula | (SiO₂, water, impurities) |
| Crystal System | Trigonal (microcrystalline) |
| Hardness (Mohs Scale) | 6.5 – 7 |
| Refractive Index | 1.48 – 1.53 |
| Specific Gravity | 2.58 – 2.64 |
| Cleavage | None, but may have shell-like fractures |
| Fracture | Chalcedony-like (smooth, waxy) |
| Inclusions | Rare, except in carved forms where filler may be used |
Sardonyx is stable under normal wear, but the porosity of natural chalcedony means that cleaning must be done with care. It is often sealed or stabilized to enhance durability and appearance, especially in cameos or carved items.
Symbolism and Metaphysical Beliefs
Peridot: A Stone of Healing and Harmony
Peridot has long been associated with positive energy, healing, and spiritual balance. In ancient Egypt, it was considered the “gem of the Sun” and believed to ward off the Evil Eye. The Egyptians also used peridot in ceremonial settings, particularly during sun worship rituals.
In medieval Europe, peridot was said to bring wealth and good fortune to those born under Mars and Mercury, and it was often used in protective talismans for travelers. Its association with the Sun also linked it to renewal, vitality, and mental clarity.
From a modern metaphysical perspective, peridot is thought to:
- Elevate self-esteem and independence
- Encourage emotional healing
- Promote peace and calm in relationships
- Absorb and redirect negative energies
Due to its vibrant green color, peridot is also linked to nature, growth, and abundance, making it a popular choice for those seeking spiritual and emotional renewal.
Spinel: The Emotional Elixir
Spinel is considered one of the most emotionally resonant gemstones, especially in red and pink varieties, which are often linked to love, courage, and emotional strength.
- Red spinel is thought to assist with blood health, vitality, and physical stamina. It is also believed to help balance internal energy, ease feelings of anger, and promote emotional stability in relationships.
- Pink spinel is associated with love, compassion, and renewal of relationships, often used as a symbol in romance and friendship.
- Blue and violet spinel is connected to spirituality, communication, and truth, and can be used in chakra healing focused on the throat or third eye.
Spinel is particularly valued as a September birthstone and 22nd anniversary gem, which underscores its symbolic role in enduring love and commitment.
Sardonyx: A Stone of Protection and Willpower
Sardonyx has been used since ancient times as a protective and grounding stone. Romans and Greeks attributed it with abilities to inspire bravery, ward off greed, and help with difficult decisions.
- Sardonyx is particularly favored in signet rings, where its non-stick surface to hot wax made it a practical and symbolic tool.
- It is also believed to strengthen willpower, aid in decision-making, and improve communication between people.
In esoteric traditions, sardonyx is connected to the root and solar plexus chakras, helping to anchor the user in the present and boost personal power and resilience.
Care and Cleaning
Peridot: Gentle Handling for a Delicate Gem
- Hardness: 6.5–7 on the Mohs scale
- Cleavage: Perfect in two directions (easily chipped)
- Cleaning: Avoid ultrasonic or steam cleaners. Use mild soapy water with lukewarm water.
- Storage: Store peridot separately from harder gemstones in a soft cloth or padded container to prevent scratching and chipping.
Because of its cleavage, peridot should never be subjected to impact or pressure. It is best suited for pendants and earrings as opposed to rings and bracelets, where it is at greater risk of damage.
Spinel: Durable and Easy to Maintain
- Hardness: 8 on the Mohs scale
- Cleavage: No cleavage, may have fractures
- Cleaning: Can be cleaned with ultrasonic or steam cleaners, though fractured stones should only be cleaned gently in soapy water.
- Heat Sensitivity: High heat can fade some colors, especially red and purple tones.
Spinel is a versatile gem that can be worn daily, and its lack of cleavage makes it resilient to wear and tear. Avoid exposure to extreme heat, particularly if the stone is colored in red or pink.
Sardonyx: Durable and Resilient
- Hardness: 6.5–7 on the Mohs scale
- Cleavage: None, but may have fractures due to its porous structure
- Cleaning: Use mild soap and water with a soft cloth. Avoid steam or ultrasonic cleaners.
- Durability: Sardonyx is suitable for jewelry and carvings, but porosity means that it may absorb dirt more easily over time.
Because sardonyx is often used in carvings or sculptures, it is sometimes treated with sealants or resins to increase durability and appearance.
Conclusion
The August birthstones—peridot, spinel, and sardonyx—each represent a unique and compelling facet of the world of gemstones. Whether it is the cosmic origins of peridot, the historical misclassifications of spinel, or the timeless elegance of sardonyx, these gems offer a rich blend of beauty, history, and symbolism.
As the only month associated with three birthstones, August provides a broad spectrum of choices—from the vivid, sunny greens of peridot, to the fiery reds and pinks of spinel, to the banded beauty of sardonyx. Each stone brings with it centuries of lore, scientific fascination, and aesthetic appeal, ensuring that their popularity is unlikely to wane.
For those looking for a meaningful and visually striking gem to celebrate August birthdays or anniversaries, these three stones provide endless options. Understanding their properties, provenance, and symbolic meaning enhances not only the appreciation of these gems but also the value and significance of the jewelry in which they are set.
Whether you’re a gemstone collector, a jewelry buyer, or simply curious about the history of your birthstone, the August birthstones offer a fascinating journey into the heart of mineralogy, design, and cultural tradition.