For those born in August, the selection of birthstones is unusually rich: three distinct gems—peridot, spinel, and sardonyx—share the honor. Each of these gemstones brings with it a unique history, a range of physical and optical properties, and a deep connection to various cultural and symbolic meanings. From the fiery reds of spinel to the vivid greens of peridot and the multicolored layers of sardonyx, August birthstones offer a compelling combination of beauty and significance. This article provides a detailed exploration of these three gemstones, grounded in historical references, geological information, and modern gemological insights.
August’s birthstones have not always been the same. While peridot has long been known for its lush green tones and cosmic origins, spinels, once mistaken for rubies and other precious stones, are newly recognized as a modern birthstone for August. Sardonyx, often overlooked in contemporary discussions, is one of the oldest birthstones on record, with roots in biblical traditions and ancient rituals. Together, they encapsulate the diverse history and evolution of gemstone symbolism.
This article delves into each stone's origin, physical characteristics, cultural lore and metaphysical properties, and practical care guidelines. Whether you are a gemstone collector, a jewelry buyer, or simply curious about the significance of your birthstone, this guide offers a comprehensive look at the gemstones associated with the month of August.
History and Lore
Sardonyx: The Oldest August Birthstone
Sardonyx is the most ancient of the three August birthstones. Its name is derived from the Greek words sardes (a region in Asia Minor where it was first found) and onyx (a banded stone). Mentioned as one of the stones in the high priest’s breastplate in the Bible, sardonyx has been revered for thousands of years across multiple civilizations. It was also one of the foundation stones of Jerusalem, according to historical accounts.
Its popularity surged in ancient Rome, where it was used extensively in cameos, signet rings, and other forms of carving. These carvings were often used as seals and were believed to have protective qualities. The stone was associated with courage and strength, and it was thought to promote the courage needed to express love freely.
The historical misidentifications of other gemstones include topaz being considered synonymous with peridot, and spinel being mistaken for ruby or sapphire during the medieval and Renaissance periods. Sardonyx, on the other hand, maintained its distinct identity even as it became a staple in royal and religious jewelry.
Peridot: The Gem of the Sun
Known for its vivid green color, peridot is a gem-quality form of the mineral olivine. The term "peridot" is derived from the Arabic faridat, meaning "gem." Historically, peridot was known as “chrysolite” due to its yellowish-green hue. However, this name is now reserved for a less gemmy form of the mineral.
Peridot has a storied past in ancient Egypt, where it was mined on the desert island of Zabargad in the Red Sea. The island, known for its harsh conditions, provided some of the finest-quality peridot. The gem was revered not only for its beauty but also for its association with the sun. According to some accounts, the Egyptians referred to peridot as the "gem of the sun," believing it carried the warmth and power of the sun’s rays.
Its historical confusion with other gems is also notable. Peridot was once mistaken for topaz, and even for emeralds. The Red Sea island of Topazios, where peridot was mined, is believed to have contributed to the name “topaz” due to its greenish color. An even more intriguing legend surrounds peridot and Cleopatra’s famous “emerald” collection; some historians suggest that many of the emeralds in her collection were actually peridot.
Spinel: The 'Ruby' That Wasn't
Spinel is the youngest of the August birthstones, added in 2016 by the American National Association of Jewelry and Allied Trades (NAJAT). Its name comes from the Latin spina, meaning "thorn," a reference to the sharp, crystalline shape in which it commonly occurs.
The history of spinel is particularly fascinating because of the long-standing mistaken identity with more famous gemstones. Many of the world’s most famous "rubies" are actually red spinel. The Black Prince’s “Ruby,” set in the Imperial State Crown of England, is a notable example. This stone, which weighs approximately 170 carats, was actually identified as spinel in the 18th century, yet it retained its placement in the crown and continues to be referred to as a ruby due to its historical significance and appearance.
The misidentifications were partly because of similar physical properties: spinel and ruby both exhibit strong red colors and often comparable hardness (though spinel is slightly softer at 8 on the Mohs scale). Another famous example is the "Timur Ruby" now housed in the British Museum, which is actually a 361-carat red spinel with a painted-on white table to mimic the appearance of a ruby cut.
Spinel has only recently begun to receive the recognition it deserves as a gemstone. Its vibrant colors, including intense reds, pinks, purples, and even blue and green varieties, make it highly desirable for contemporary jewelry. The 2016 designation as an August birthstone was a reflection of growing interest and appreciation for this underappreciated gem.
Geological Formation and Sources
Understanding the geological origins of these gemstones provides insight into their rarity and value. Each August birthstone is formed under specific conditions that contribute to its physical and visual properties.
Peridot: From Earth and Space
Peridot is one of the few gemstones with extraterrestrial origins. It forms under high-temperature conditions, typically at a depth of 25 to 50 miles below the Earth’s surface in the mantle, where it is brought to the surface by volcanic activity. The green color is due to the presence of iron and magnesium silicates.
Notably, peridot can also be found in meteorites, where it is known as pallasite, a type of stony-iron meteorite containing olivine crystals embedded in a nickel-iron matrix. Some of the most pristine peridot samples are found in the San Carlos Indian Reservation in Arizona, making it a well-known source of gem-quality material in the U.S.
Other notable sources include:
- The Red Sea island of Zabargad (an island of volcanic origin)
- Brazil
- Norway
- Sri Lanka
- Australia
- Myanmar (Burma)
- Kenya
- China
- Mexico
Each source produces peridot with slight variations in tone, hue, and clarity, depending on the geological and chemical conditions of the deposit.
Spinel: A Global Distribution
Spinel is formed in metamorphic and igneous rocks, often in association with corundum (ruby and sapphire). It is relatively uniform in structure compared to other gemstones, making it easier to identify once it has been analyzed chemically. Spinels with intense red or pink hues are particularly valuable.
The major historical and current sources of spinel include:
- Sri Lanka – known for producing vivid pink and red spinels
- Myanmar (Burma)
- Afghanistan
- Tajikistan
- Vietnam
- Tanzania
- Pakistan
Myanmar is especially notable for producing spinels with hot pink and ruby-like red tones, while Sri Lanka is famous for bi-coloured spinels showing a gradient of deep and light colors. These are known as “parti-colored” spinels and are highly prized in the jewelry trade for their unique appearance.
The geological conditions necessary for spinel formation often occur in gem-rich regions such as the Himalayan mountain chain, where intense pressure and heat have created the perfect conditions for spinel to crystallize alongside other valuable gems like ruby and sapphire.
Sardonyx: Layers of History and Geology
Sardonyx is a banded form of chalcedony, composed of microscopic quartz crystals and quartz-rich fluids that deposit in layers over thousands of years. The red and white (or brown and white) banded appearance is a result of this alternating deposition of different materials.
This gemstone is typically found in volcanic and metamorphic rocks, especially in areas with high silicon content. The presence of iron oxides in the stone results in the characteristic red and brown tones of sardonyx, while tremolite or other silicate minerals contribute to the white layers.
Modern-day sources of sardonyx include:
- India
- Brazil
- Romania
- Afghanistan
- Mexico
- Peru
Ancient sources included Ceylon (now Sri Lanka) and Persia (modern-day Iran and surrounding regions), where it was mined for use in carving and ornamental items. Due to its banded nature and workability, sardonyx has always been a popular material for cameos and engraved gems, a tradition that has continued well into the modern era.
Gemological Properties
When evaluating gemstones, professionals and buyers alike consider a range of scientific properties that define the stone's appearance, durability, and use in jewelry. Here’s a breakdown of the key characteristics of the August birthstones:
Peridot
| Property | Description |
|---|---|
| Chemical Formula | (Mg,Fe)₂SiO₄ |
| Color | Yellowish-green to vivid green (depending on iron content) |
| Hardness (Mohs) | 6.5–7 |
| Refractive Index | 1.650–1.690 |
| Luster | Vitreous (glassy) |
| Crystal System | Orthorhombic |
| Specific Gravity | 3.2–4.3 |
Peridot is relatively soft compared to more durable gems like topaz or sapphire, so it is more susceptible to scratches when worn daily. Its iron content affects not only its color but also its thermal sensitivity, which can be a concern during polishing or heat treatments.
Spinel
| Property | Description |
|---|---|
| Chemical Formula | MgAl₂O₄ (common red and pink varieties) |
| Color | Red, pink, purple, violet, blue, green, etc. |
| Hardness (Mohs) | 8 |
| Refractive Index | 1.718–1.721 |
| Luster | Vitreous to subadamant (glassy to somewhat bright) |
| Crystal System | Cubic |
| Specific Gravity | 3.6–4.0 |
Spinel is significantly harder than peridot, making it a more practical choice for everyday wear. Its variety in colors and clarity makes it an excellent choice for ring and pendant use. Spinel does not exhibit cleavage like diamonds, so it is less prone to splitting under pressure, making it a more durable option for set jewelry.
Sardonyx
| Property | Description |
|---|---|
| Chemical Nature | Microcrystalline quartz (a form of chalcedony) |
| Color | Banded red, brown, white (with bands of contrasting color) |
| Hardness (Mohs) | 6.5–7 |
| Luster | Waxy to vitreous |
| Specific Gravity | 2.58–2.64 |
Sardonyx is a silica-rich microcrystalline quartz, and like other chalcedonies, it is relatively hard and stable. The banding is the result of alternating layers of different silica-rich fluids, which deposit in clear, visible patterns over long periods. Sardonyx is well-suited for carving, engraving, and cameo work, which is one reason it was so valued in ancient times.
Symbolism and Metaphysical Beliefs
The beliefs surrounding these stones have evolved over time, but their significance in cultural traditions and spiritual practices remains strong. Many of the August birthstones are associated with qualities such as courage, protection, emotional strength, and clarity of mind.
Peridot
Peridot has long been associated with positive energy, renewal, and vitality. In many ancient cultures, it was believed to ward off nightmares and darkness, and to help the wearer maintain a calm and peaceful mind. Some legends suggest that peridot crystals found in volcanic rock were gifts from the sun god, and that these stones held the power to bring joy and ward off despair.
Modern metaphysical practitioners continue to regard peridot as a stone of manifestation, growth, and emotional healing. It is often recommended for people struggling with fear of change, insecurity, or emotional blocks, as it is believed to enhance self-esteem and encourage clarity.
Peridot is also one of the traditional 16th anniversary gems, symbolizing long-lasting love and enduring relationships.
Spinel
Spinel is often considered a stone of vitality and endurance, capable of enhancing physical and mental energy. It is also believed to fortify the will and encourage one to overcome obstacles. As a gem that was once mistaken for ruby and diamond, spinel has developed a rich resonance with transformation and mistaken identity, making it a powerful symbol for those who are seeking self-discovery and clarity in their lives.
Red spinel, in particular, is associated with passion, courage, and bold action, while pink and purple spinel are attributed with romantic energies and emotional depth. Spinel is also considered a healing stone, and many believe it can help alleviate anxiety, especially when dealing with conflict or pressure.
It is the 22nd wedding anniversary gemstone, representing devotion and enduring love through time.
Sardonyx
Sardonyx has long been regarded as a stone of courage, success, and protection. In Greek and Roman times, it was especially valued by those in positions of leadership or those preparing for battle, as it was believed to boost confidence and reduce fear. Sardonyx was considered a powerful token for those embarking on journeys, whether physical or spiritual.
The stone is also known as the gem of love and partnership, and it is said to help express feelings of love and devotion freely and sincerely. Its banded pattern symbolizes stability and balance, making it especially favored by those seeking emotional harmony and success in their endeavors.
Sardonyx is also believed to offer protection from curses and negative energies, which is one reason it was commonly used in protective amulets and talismans in ancient times.
Care and Cleaning
Proper care is essential to preserving the appearance and durability of gemstone jewelry. The care methods vary slightly depending on the gem, but the following general guidelines are recommended for the three August birthstones.
Peridot
Peridot is a relatively resilient stone, but it is not as hard as diamonds or sapphires, so it should be handled with care. It is sensitive to excessive heat, which can cause it to become dull or discolored. Avoid placing peridot in hot environments such as direct sunlight or a heated jewelry box.
Cleaning Method:
- Use a soft, lint-free cloth with ammonia-free jewelry cleaning solution or a gentle soap and water bath.
- Avoid ultrasonic cleaners and steam cleaning, as they may cause damage, especially if the stone has surface fractures.
Spinel
Spinel is one of the more durable gemstones for August, with a Mohs hardness of 8, comparable to topaz. This makes it suitable for daily wear in rings and pendants.
Cleaning Method:
- Spinel can be cleaned with warm soapy water and a soft brush to remove dirt or oils.
- Ultrasonic and steam cleaners are generally safe for spinel, unless the stone has inclusions or surface damage that might be exacerbated by such treatments.
Sardonyx
Banded stones like sardonyx are best avoiding harsh treatments, but its moderate hardness (6.5–7) makes it relatively resilient. Sardonyx can be lightly cleaned with a soft cloth and mild detergent solution, but should not be exposed to harsh chemicals or abrasive cleaners.
Cleaning Method:
- Wipe with a soft, damp cloth and a mild detergent.
- Avoid over-scrubbing, especially in carved or decorative areas.
Conclusion
The three August birthstones—peridot, spinel, and sardonyx—each offer a unique blend of history, beauty, and symbolism. From the protective powers of sardonyx to the fiery brilliance of spinel and the sun-like glow of peridot, these gems reflect the diverse meanings and uses attached to birthstones throughout history.
Whether you are drawn to the vibrant green of peridot, the intense reds of spinel, or the multicolored bands of sardonyx, there is a birthstone to suit every taste and intention. With proper care and an appreciation of their heritage and properties, these gems can remain cherished symbols for generations.
Understanding their origins, properties, and cultural significance not only enhances your appreciation for these stones but also connects you to the long history of gemstone symbolism and use.