The month of August is uniquely endowed with three distinct birthstones: Peridot, Spinel, and Sardonyx. Each of these gemstones possesses a unique geological origin, a rich history, and specific gemological characteristics that set them apart in the world of colored stones. While modern lists often highlight Peridot and Spinel for their vibrant colors and durability, Sardonyx holds the distinction of being the original August birthstone, with a history spanning over four millennia. This article provides an in-depth exploration of these three gems, examining their historical significance, geological formation, gemological properties, and their roles in both ancient lore and contemporary jewelry.
The diversity offered by August’s birthstones allows for a wide range of personal expression. From the olive-green hues of Peridot, formed deep within the Earth’s mantle and even found in meteorites, to the fiery reds of Spinel, often mistaken for the finest ruby, and the banded layers of Sardonyx, prized by ancient Roman generals for seals and cameos, these stones offer something for every enthusiast. Understanding the distinct characteristics of each is essential for collectors, jewelers, and those seeking a personal connection to their birthstone. This guide will navigate the science, history, and symbolism behind Peridot, Spinel, and Sardonyx.
Peridot: The Gem of the Sun
Peridot stands out as the most famous of the August birthstones, celebrated for its distinctive olive to lime green color. Unlike many gemstones that display a spectrum of colors, Peridot is known to occur in only one color family, though the intensity can vary significantly. The source of this captivating green is the presence of iron within the gem’s chemical structure; the amount of iron dictates whether the stone appears a pale yellow-green or a deep, rich olive.
History and Lore
Peridot’s history is as ancient and fascinating as the gem itself. It has been cherished for thousands of years, with records of its use dating back to ancient civilizations. One of the most prominent historical associations is with ancient Egypt, where Peridot was referred to as the “gem of the sun.” The Egyptians believed the stone possessed powerful protective properties, using it to ward off evil spirits and nightmares. It was mined on the island of Zabargad (formerly Topazios) in the Red Sea, a source that was so significant it led to historical confusion regarding the name "topaz."
This confusion is a notable aspect of Peridot's history. The Red Sea island of Topazios was actually a source of Peridot, not Topaz, leading to centuries of misidentification. Furthermore, the 200 carats of gems adorning the Shrine of the Three Holy Kings in Germany’s Cologne Cathedral, long believed to be emeralds, were later identified as Peridot. Some historians even speculate that Cleopatra’s famous collection of emeralds may have actually been Peridot.
The Romans also held Peridot in high esteem, calling it the “Evening Emerald.” They noted that the gem’s green color did not darken at night but continued to glow vibrantly under candlelight, making it a popular choice for jewelry worn during evening festivities. Its historical use extends to the palaces of the Ottoman Empire and has been found in ancient Persian and Greek jewelry, solidifying its status as a gem of antiquity.
Geological Formation and Sources
Peridot, a variety of the mineral olivine, is formed under extreme geological conditions. It is one of the few gems found in the hardened lava that carries it from deep within the Earth’s mantle to the surface. This unique formation process makes it a gem of volcanic origin. Perhaps even more remarkably, Peridot is also found in pallasite meteorites—stony-iron meteorites that formed in the early solar system—making it one of the few gems known to originate from outer space.
The primary commercial sources of Peridot include Pakistan, which is renowned for producing large, high-quality crystals; Arizona in the United States; and Myanmar (Burma). Other sources include Australia, Brazil, China, Kenya, Mexico, Sri Lanka, and Tanzania. The gem from Arizona is often found in basaltic rock, while the finest material from Pakistan and Afghanistan is typically found in marble.
Gemological Properties
Peridot is a relatively hard gemstone, making it suitable for various types of jewelry. Its distinct color and clarity make it a favorite for rings, pendants, and earrings.
| Property | Details |
|---|---|
| Mineral | Olivine (Magnesium Iron Silicate) |
| Color | Olive green, yellowish-green, to brownish-green |
| Hardness (Mohs Scale) | 6.5 to 7 |
| Crystal System | Orthorhombic |
| Refractive Index | 1.642 to 1.686 |
| Specific Gravity | 3.34 to 3.48 |
| Transparency | Transparent to translucent |
| Sources | Pakistan, Arizona (USA), Myanmar, Australia, Brazil, China, Kenya, Mexico, Sri Lanka, Tanzania |
Symbolism and Metaphysical Beliefs
Beyond its historical protective qualities, Peridot is associated with positivity, healing, and prosperity. It is often linked to the sun and light, believed to bring warmth and good fortune to the wearer. In modern crystal healing, Peridot is thought to alleviate stress, inspire creativity, and promote growth and renewal. Its connection to the heart chakra makes it a stone of compassion and emotional balance.
Care and Cleaning
With a hardness of 6.5 to 7 on the Mohs scale, Peridot is durable enough for daily wear but can be susceptible to scratches and abrasions if not handled with care. It is advisable to store Peridot jewelry separately to prevent contact with harder stones. To clean Peridot, use warm, soapy water and a soft brush. Avoid harsh chemicals, extreme temperature changes, and ultrasonic cleaners, as these can damage the stone.
Spinel: The Underappreciated Beauty
For many years, Spinel was the unsung hero of the gem world, often mistaken for other, more famous stones. Its recent elevation to official August birthstone status has brought it the recognition it deserves. Spinel is prized for its wide range of vibrant colors and its exceptional durability.
History and Lore
Spinel’s history is marked by a case of mistaken identity. For centuries, the most famous red spinels were believed to be rubies. The Black Prince’s Ruby, a massive 170-carat red gem that adorns the British Imperial State Crown, is, in fact, a red spinel. Similarly, the Timur Ruby, a 361-carat gem, is also a spinel. These historical gems were sourced from the famous Badakhshan region of Central Asia (modern-day Tajikistan and Afghanistan).
The name "spinel" is derived from the Latin word spina, meaning thorn, likely referring to the shape of its crystals. It wasn't until the 19th century that spinel was recognized as a distinct mineral species from ruby and corundum. Its history as a "super-ruby" has made it a gem of great historical interest, and its true identity is now celebrated by gemologists and collectors alike.
Geological Formation and Sources
Spinel is a magnesium aluminum oxide with a cubic crystal system. It forms under high-temperature and low-pressure conditions, typically in metamorphic rocks like marble and alluvial deposits. The gem’s vibrant colors are caused by trace elements such as chromium (for red and pink), iron (for blue and green), and vanadium.
The most famous source for red spinel is the Badakhshan region, which has been a source of spinel for over a thousand years. Other significant sources include: * Myanmar (Burma): Known for producing some of the finest "ruby-like" red spinels. * Vietnam: A source of vibrant red and pink spinels. * Sri Lanka: Produces a wide variety of colors, including blue, purple, and pink. * Tajikistan: Home to the Pamir Mountains, where large crystals are found. * Pakistan: The Swat Valley is a source of high-quality spinel. * United States: Occurs in Montana and North Carolina.
Gemological Properties
Spinel is an excellent gemstone for jewelry due to its hardness, lack of cleavage, and high refractive index. It offers an alternative to ruby and sapphire with its own unique character.
| Property | Details |
|---|---|
| Mineral | Spinel (Magnesium Aluminum Oxide) |
| Color | Wide range: Red, pink, blue, purple, black, colorless, and green |
| Hardness (Mohs Scale) | 8 |
| Crystal System | Cubic |
| Refractive Index | 1.718 |
| Specific Gravity | 3.60 |
| Transparency | Transparent to translucent |
| Sources | Myanmar, Vietnam, Sri Lanka, Tajikistan, Pakistan, Tanzania, United States |
Symbolism and Metaphysical Beliefs
As a more recently recognized birthstone, Spinel lacks the extensive ancient lore of Peridot or Sardonyx. However, it has quickly developed a modern symbolism. Red spinel, with its connection to ruby, is associated with passion, vitality, and energy. Different colors of spinel are linked to various chakras and are believed to inspire inspiration, relieve stress, and rejuvenate the body and spirit. Its lack of established historical baggage allows it to be seen as a stone of new beginnings and modernity.
Care and Cleaning
Spinel is a very durable gemstone with a hardness of 8 on the Mohs scale, making it resistant to scratching and suitable for all types of jewelry. It also has no cleavage, meaning it is less likely to chip or break upon impact. Cleaning is straightforward: use warm, soapy water and a soft brush. It is generally stable and unaffected by heat or light, but ultrasonic cleaners should be used with caution, especially if the stone has fractures or inclusions.
Sardonyx: The Original August Birthstone
Sardonyx is the original birthstone for August, with a history that predates the other two gems by millennia. It is a variety of chalcedony, which is a microcrystalline form of quartz, and is characterized by its distinctive banding.
History and Lore
Sardonyx has been used for over 4,000 years. Its name comes from the Greek words sard (a type of chalcedony) and onyx (meaning nail or veined stone). The stone is composed of layers of sard (a reddish-brown chalcedony) and onyx (a white or black chalcedony), creating a beautiful contrast in its bands.
The ancient Romans were among the most avid users of Sardonyx. They prized it for making signet rings and cameos, as the distinct layers of color were perfect for carving intricate designs. Roman soldiers wore Sardonyx rings and amulets, believing the stone would protect them in battle and bring them courage. Its association with courage and protection made it a popular talisman throughout antiquity.
In later years, Sardonyx became a favorite stone for carving cameos and intaglios, especially during the Renaissance and Victorian eras. The stone’s ability to be easily carved and its attractive banding made it ideal for creating detailed portraits and scenes.
Geological Formation and Sources
Sardonyx is a form of banded chalcedony, a mineral in the quartz family. It forms in cavities of volcanic or sedimentary rocks as silica-rich fluids deposit layers of microcrystalline quartz. The different colors are caused by impurities in the silica, such as iron oxides for the reddish sard layers.
Major sources of Sardonyx include: * India: A primary source for high-quality Sardonyx, especially for carving. * Brazil: Produces a significant amount of banded chalcedony. * Germany: Known for historical deposits. * United States: Found in several states, including Oregon and Idaho. * Uruguay: Another source for chalcedony varieties.
Gemological Properties
Sardonyx is valued for its durability and unique appearance. As a member of the quartz family, it has a good hardness for carving and everyday wear.
| Property | Details |
|---|---|
| Mineral | Chalcedony (Microcrystalline Quartz) |
| Color | Bands of reddish-brown (sard) and white or black (onyx) |
| Hardness (Mohs Scale) | 7 |
| Crystal System | Trigonal (microcrystalline) |
| Refractive Index | 1.535 to 1.539 |
| Specific Gravity | 2.58 to 2.64 |
| Transparency | Translucent to opaque |
| Sources | India, Brazil, Germany, United States, Uruguay |
Symbolism and Metaphysical Beliefs
Sardonyx is deeply rooted in symbolism related to strength, protection, and courage. It was historically considered a stone of orators and leaders, believed to lend persuasiveness and a commanding presence. It is also associated with happiness and good fortune in marriage. In modern metaphysical practices, Sardonyx is thought to promote integrity, virtuous conduct, and stability. It is often used as a grounding stone, helping to build self-confidence and overcome fears.
Care and Cleaning
With a hardness of 7 on the Mohs scale, Sardonyx is durable and suitable for a variety of jewelry applications, especially carved pieces. It is resistant to everyday wear and tear. To clean Sardonyx, simply use warm, soapy water and a soft cloth or brush. It can be safely cleaned with an ultrasonic cleaner, but it is best to avoid sudden temperature changes and harsh chemicals to maintain its luster and the sharpness of its bands.
Conclusion
The birthstones of August—Peridot, Spinel, and Sardonyx—offer a remarkable trio of gems, each with a unique story and set of attributes. Peridot captivates with its single-minded green hue and extraterrestrial origins, earning its place as the "gem of the sun." Spinel provides a vibrant and durable alternative to ruby, shaking off centuries of mistaken identity to claim its own legacy. Sardonyx, the original August stone, connects the modern wearer to an ancient past of Roman generals and Renaissance carvers through its striking bands.
Together, these three stones provide a breadth of choice in color, history, and symbolism. Whether one is drawn to the protective lore of ancient Egypt, the historical intrigue of the British Crown Jewels, or the classical art of the cameo, August’s birthstones deliver beauty and significance. For the gem enthusiast, jewelry buyer, or student of gemology, understanding the distinct qualities of Peridot, Spinel, and Sardonyx is key to appreciating the full scope of what this month has to offer.