Peridot, with its signature lime-green hue, stands as one of the few gemstones in the world that appears in only one color. Unlike many of its counterparts that owe their chromatic diversity to trace elements, the peridot’s vibrant color is an intrinsic part of its fundamental chemical composition. This striking gem, the birthstone for the month of August, possesses a rich and storied history that stretches back millennia, adorning the treasures of ancient pharaohs and surviving the shipwrecks of Spanish conquistadors.
This guide delves into the world of peridot, exploring its unique geological origins, its celebrated journey through human history, and its modern significance as a cherished birthstone. We will examine its gemological properties, offer practical advice for its care, and navigate the contemporary market where this "evening emerald" continues to captivate gemstone enthusiasts and jewelry buyers alike.
The August Birthstone: A History Forged in Fire and Earth
The story of peridot is deeply intertwined with the history of human civilization, with evidence of its use dating back to the ancient Egyptians. Often referred to by the ancient Egyptians as the "gem of the sun," peridot was believed to offer protection against evil spirits and nightmares. It was a stone of significant power and prestige, prominently featured in the jewelry of high-ranking individuals and used to decorate sacred sites. The most famous historical source for peridot was Zabargad, a small, desolate island in the Red Sea. For over 3,500 years, this island was the primary source of the gem, with mining operations dating back to as early as 1500 B.C. The intense, fiery conditions of the island's formation are mirrored in the gem's own volcanic origins.
The allure of peridot extended far beyond Egypt. The Romans were avid collectors, valuing the gem for its supposed medicinal properties and its ability to ward off enchantment. Historical accounts suggest that the Romans believed peridot could be used to cure asthma and other ailments of the lungs, and that it was most effective when set in gold. This belief in its healing power persisted for centuries, with the stone being ground into a powder and used as a remedy for a variety of conditions.
The journey of peridot into the modern consciousness took a dramatic turn in the 20th century. While known for centuries, a significant surge in its popularity occurred after a massive deposit was discovered in Arizona in the 1890s. This discovery, particularly on the San Carlos Apache Reservation, made peridot more accessible to a wider audience. However, the most romantic chapter in the gem's modern history is undoubtedly linked to the infamous wreck of the Spanish galleon Nuestra Señora de Atocha. Sunk in a hurricane off the coast of Florida in 1622, the ship lay undiscovered for over three centuries. When treasure hunter Mel Fisher finally located the wreck in 1985, it yielded a staggering treasure trove, including a fortune in peridot. The gemstones recovered from the Atocha, with their unique character and historical provenance, became legendary and fueled a renewed global interest in this captivating green gem. Today, peridot is officially recognized as the birthstone for August, a designation solidified by the American Gem Trade Association (AGTA) and other major gemological organizations.
Geological Formation and Global Sources
Peridot's origin story is as unique as its color. It is one of the few gemstones that is formed not in the Earth's crust, but deep within the planet's mantle. It is brought to the surface by volcanic activity, often found in rocks known as peridotite. This places it in a rare category of gems, alongside diamonds, that originate from great depths. The gem is, in fact, the gem-quality variety of the mineral olivine, a common mineral found in the Earth's mantle and in many meteorites.
The primary global sources for peridot today reflect this geological reality. The most significant commercial deposits are located in the United States, specifically in Arizona and New Mexico, where peridot is mined from volcanic formations. These American deposits are known for producing large, high-quality stones, though they often exhibit a slightly lighter, more yellowish-green hue compared to peridots from other localities.
Other notable sources include Pakistan, particularly the Kashmir region, which has become famous for producing exceptionally fine peridot with a rich, vivid green color and high clarity. Myanmar (Burma) is another historically important source, known for its gem-quality peridot. In China, peridot is mined in the Xinjiang region, and smaller deposits have been found in Australia, Brazil, Egypt, Kenya, Mexico, Norway, and South Africa.
The gem's formation can also occur in an unusual and fascinating way: as a result of extraterrestrial events. Peridot has been found in many pallasite meteorites, which are stony-iron meteorites that formed at the core-mantle boundary of a protoplanet that was destroyed in a collision billions of years ago. These "space peridots" provide a direct physical link between the gem and the formation of our solar system, adding another layer of wonder to its already rich story.
Gemological Properties: The Science of a Single-Color Gem
Peridot possesses a set of distinct gemological properties that define its identity and distinguish it from other green gemstones like emerald or tourmaline. Understanding these characteristics is crucial for gemologists, collectors, and anyone looking to purchase this August birthstone.
Color: The most defining characteristic of peridot is its color. It is the only gemstone (aside from the diamond) that is found in only one color: a range of green. This color is a result of its chemical composition, specifically the presence of iron. The hue can vary from a light, yellowish-green to a deep, olive green. The most prized color is a rich, pure grass green, with stones exhibiting a strong saturation and medium-dark tone commanding the highest prices.
Hardness and Durability: On the Mohs scale of hardness, peridot ranks between 6.5 and 7. While this makes it a reasonably durable gemstone suitable for everyday wear in rings, earrings, and pendants, it is softer than sapphire or ruby (both ranking at 9) and diamond (10). This means it can be susceptible to scratching if not handled with care. It also has no cleavage, which is an advantage, but it is brittle and can be chipped or cracked by a hard blow.
Chemical Composition: Peridot is the gemological variety of the mineral olivine, with a chemical formula of (Mg, Fe)₂SiO₄. It is an iron magnesium silicate. The ratio of iron to magnesium determines the exact shade of green; higher iron content generally results in a deeper green color.
Clarity and Inclusions: Peridot is typically found as an "eye-clean" gemstone, meaning that inclusions are not usually visible to the naked eye. However, like most natural gems, it does contain internal characteristics. The most common inclusions in peridot are small, lily-pad-shaped or discoid inclusions, which are remnants of the gem's formation process. These inclusions can sometimes be used by gemologists to help distinguish natural peridot from synthetic or imitated materials.
Refractive Index and Optical Properties: Peridot is a doubly refractive gemstone, meaning that light entering the stone is split into two rays. This property contributes to its brilliance. It has a refractive index that ranges from approximately 1.65 to 1.69. It is also pleochroic, meaning it can show slightly different shades of green when viewed from different crystal directions, though this is often not noticeable to the casual observer.
Summary of Key Gemological Properties
| Property | Details |
|---|---|
| Mineral | Olivine (Magnesium Iron Silicate) |
| Chemical Formula | (Mg, Fe)₂SiO₄ |
| Color | Green (only one color; shades from yellowish-green to olive) |
| Mohs Hardness | 6.5 - 7 |
| Crystal System | Orthorhombic |
| Refractive Index | 1.65 - 1.69 |
| Specific Gravity | 3.34 |
| Sources | USA (Arizona), Pakistan, Myanmar, China, Australia, Brazil, Egypt, Kenya, Mexico, Norway, South Africa |
Symbolism and Metaphysical Beliefs
Across cultures and through the ages, peridot has been imbued with a wide array of symbolic meanings and metaphysical powers. Its vibrant green color, reminiscent of new growth and vitality, has naturally associated it with themes of life, renewal, and prosperity.
In ancient times, peridot was considered a powerful talisman. The Egyptians believed it protected its wearer from the terrors of the night and could ward off evil spirits. It was often set in gold, which was thought to amplify its protective powers. The Greeks and Romans also valued the stone for its protective qualities, believing it could dispel fear and enchantment.
Beyond protection, peridot has long been associated with healing and well-being. As mentioned, it was historically used as a remedy for a variety of physical ailments. It was believed to strengthen the eyes, stop asthma, and cure liver ailments. The stone was also thought to have a calming effect, promoting sleep and bringing peace to the mind.
In modern crystal healing and metaphysical traditions, peridot is known as the "Stone of Compassion." It is believed to open the heart to new experiences, foster love, and encourage forgiveness. It is also associated with abundance and prosperity, said to attract good fortune and success to its wearer. As the birthstone for August, it is thought to bring good luck and positive energy to those born in that month, promoting growth, renewal, and a sense of well-being.
Care and Cleaning: Preserving Peridot's Brilliance
Given its specific gemological properties, particularly its hardness and potential brittleness, peridot requires careful handling and proper cleaning to maintain its beauty and integrity over time.
Daily Wear Considerations: While peridot is suitable for rings and other jewelry worn daily, it is advisable to be mindful of its exposure to hard knocks or abrasive surfaces. When not being worn, it should be stored separately in a soft cloth pouch or in a lined jewelry box to prevent it from being scratched by other, harder gemstones.
Cleaning Instructions: Peridot is relatively easy to clean, but harsh chemicals and extreme temperatures should be avoided. * Best Method: The safest way to clean peridot jewelry is with warm, soapy water and a soft brush, such as a baby toothbrush. Gently scrub the stone and its setting, then rinse thoroughly with clean water to remove any soap residue. * What to Avoid: Avoid using ultrasonic cleaners, as the vibrations can potentially damage the stone, especially if it has any internal fractures. Steam cleaners are also not recommended due to the risk of thermal shock. Additionally, avoid exposing peridot to harsh chemicals like bleach, chlorine, or strong acids, as these can damage both the gem and its metal setting. It is also wise to remove peridot jewelry before engaging in activities like gardening, heavy cleaning, or sports.
By following these simple care guidelines, the vibrant green beauty of a peridot can be preserved for generations, continuing its legacy as a gem of life, light, and enduring appeal.
Conclusion
Peridot is a gemstone of remarkable character, defined by its single, vibrant green color and its extraordinary origin deep within the Earth's mantle. From its ancient role as a protective talisman for the Egyptians to its modern status as the cherished birthstone for August, its history is as rich and compelling as its hue. Its unique geological journey, brought to the surface by volcanic fire, and its occasional extraterrestrial origin in meteorites, set it apart in the mineral kingdom. While its relative softness requires mindful care, its beauty and symbolic association with compassion and abundance ensure its enduring popularity. Peridot remains a gemstone that is both scientifically fascinating and culturally significant, offering a touch of living green to all who wear it.