The month of August is uniquely associated with three distinct birthstones: Peridot, Sardonyx, and Spinel. Among these, Peridot stands out with its distinctive and captivating lime-green hue, a color that has been cherished for millennia. Unlike many other gemstones, Peridot is found in only one color family—a brilliant olive to lime green—caused by the presence of iron within its crystal structure. Its vibrant color, which does not require any heat treatment or enhancement to achieve its beauty, has made it a favorite of royalty and gem connoisseurs throughout history. This article delves into the rich history, geological origins, gemological properties, and enduring symbolism of Peridot, the primary modern birthstone for August.
History and Lore
Peridot’s story stretches back to antiquity, with evidence of its use dating back to the ancient Egyptians. Often referred to as the "Gem of the Sun," ancient Egyptians believed that Peridot’s radiant green glow was a solidified ray of the sun. It was highly prized and used extensively in jewelry, including the famous large Peridots that adorned the shrines of Egyptian temples. Historical accounts suggest that Cleopatra’s famed emerald collection may have actually contained large, magnificent Peridots, as the ancient world often confused the two green gems. The primary source for these ancient gems was the island of Zabargad (also known as St. John’s Island) in the Red Sea, which was the world’s primary source of Peridot for centuries.
Throughout history, Peridot has been associated with light and positivity. During the Middle Ages, Peridots were brought to Europe from the Middle East, where they were used in church ornamentation and set into the gold of ecclesiastical rings. The Romans held Peridot in high regard, calling it "Topazion," and believed it had the power to dispel darkness and fear. They wore it as a protective amulet against evil spirits and nightmares. This association with light and protection continued into the Renaissance, where it was believed to promote friendship and peace, while also warding off envy and anger.
The journey of Peridot to becoming a modern birthstone is a relatively recent development. The concept of birthstones has ancient roots, but the standardized list used today was largely established in 1912 by the American National Association of Jewelers. Peridot was officially designated as the birthstone for August on this list. While Sardonyx was the traditional birthstone, Peridot’s popularity and distinct beauty secured its place as the primary modern choice. Today, it is celebrated not only as the August birthstone but also as the gem for the 16th wedding anniversary.
Geological Formation and Sources
Peridot is one of the few gemstones that is formed deep within the Earth's mantle and brought to the surface by volcanic activity. It is a variety of the mineral olivine, which is a common rock-forming mineral. Its formation occurs in two main geological settings: in peridotite rocks brought up from the mantle through tectonic processes and in lava from deep-source volcanoes. This unique origin means that Peridot crystals can be found within volcanic rocks, sometimes even as large enough crystals to be cut into gemstones of significant carat weight.
Unlike many other gemstones that require extensive cutting and polishing to reveal their beauty, the color of Peridot is naturally stable and does not fade or change with exposure to light or heat. This makes it a relatively stable gem for jewelry use. The gem’s formation can also occur in metamorphic rocks, such as those created by the alteration of iron-rich silicate minerals.
Historically, the primary source of Peridot was the island of Zabargad in the Red Sea. This source was known for producing high-quality gems that were traded throughout the ancient world. However, the island's production declined over time. In the modern era, the most significant sources of Peridot are located in the United States, particularly in the San Carlos Apache Reservation in Arizona. This region is known for producing a large quantity of Peridot, though the stones are often smaller in size.
Other notable sources of Peridot include Myanmar (Burma), Pakistan, and China. Peridot from these locations can produce gems of exceptional quality and larger sizes. The gem is also found in Australia, Brazil, and South Africa. The geographic distribution of Peridot is a testament to its unique volcanic origins, with deposits often linked to areas of significant geological activity.
Gemological Properties
Peridot possesses a distinct set of gemological characteristics that define its identity and value. Understanding these properties is essential for gemologists, jewelers, and collectors alike.
Color: The most defining characteristic of Peridot is its color. It is one of the few gemstones that occurs in only one color: green. The shade of green can vary from a light, yellowish-green to a deep, olive green. The most prized color is a rich, vibrant lime green with no hints of brown or yellow. The color is caused by the presence of iron (Fe) in its chemical composition. The intensity of the green is directly related to the amount of iron present.
Hardness and Durability: On the Mohs scale of hardness, Peridot rates between 6.5 and 7. This makes it a moderately durable gemstone, suitable for all types of jewelry. However, its hardness is lower than that of sapphire or ruby (9) and diamond (10), so it can be susceptible to scratching if not handled with care. It also has no cleavage, meaning it does not have any internal planes of weakness that would cause it to split easily, but it has poor toughness, making it more prone to chipping or breaking upon impact.
Chemical Composition: Peridot is the gem-quality variety of the mineral olivine. Its chemical formula is (Mg, Fe)₂SiO₄, which represents a solid solution between the magnesium-rich forsterite and the iron-rich fayalite end-members. The specific shade of green is determined by the ratio of iron to magnesium.
Refractive Index and Other Properties: Peridot has a refractive index that ranges from 1.654 to 1.690. It is doubly refractive, meaning light splits into two rays as it passes through the crystal. It has a specific gravity of 3.34 to 3.48. These optical properties help gemologists identify the stone and distinguish it from other green gems like emerald or tourmaline.
The following table summarizes key gemological data for Peridot:
| Property | Description / Value |
|---|---|
| Mineral | Olivine |
| Chemical Formula | (Mg, Fe)₂SiO₄ |
| Color | Olive green to lime green |
| Mohs Hardness | 6.5 – 7 |
| Refractive Index | 1.654 – 1.690 |
| Specific Gravity | 3.34 – 3.48 |
| Crystal System | Orthorhombic |
Symbolism and Metaphysical Beliefs
Peridot has been imbued with symbolic meaning and metaphysical power for thousands of years. Its connection to light, the sun, and nature has made it a gem of positive energy and healing.
In ancient times, Peridot was considered a powerful talisman. The Egyptians believed it protected its wearer from evil spirits and could be used to conjure storms if thrown into a river. It was also thought to have the power to heal sickness and bring good fortune. Its association with the sun led to the belief that it could dispel darkness and fear, both literally and metaphorically. Peridot was often set in gold, which was believed to enhance its protective powers.
The Romans also valued Peridot for its protective qualities, believing it could ward off evil spirits and prevent nightmares. They called it the "evening emerald" because its green color was thought to be more visible in low light. This association with evening and night made it a popular choice for amulets meant to protect against the dangers of the dark.
In modern crystal healing and metaphysical beliefs, Peridot is known as a stone of compassion and emotional clarity. It is believed to open the heart chakra, promoting forgiveness, understanding, and compassion for oneself and others. It is also associated with abundance and prosperity, said to attract wealth and success. Many believe that wearing Peridot can reduce stress, alleviate jealousy and resentment, and bring a sense of peace and renewal.
Peridot is also linked to the natural world and the renewal of life. Its vibrant green color is reminiscent of new growth in spring, symbolizing rebirth and new beginnings. This makes it a fitting symbol for anyone embarking on a new chapter in their life or seeking to shed old habits and embrace a more positive outlook.
Care and Cleaning
Due to its physical properties, Peridot requires careful handling and specific cleaning methods to maintain its brilliance and integrity. While it is suitable for everyday wear in jewelry such as rings, earrings, and pendants, its moderate hardness and poor toughness mean it can be damaged by hard blows or sharp impacts.
Cleaning: The best way to clean Peridot is with warm, soapy water and a soft brush. Gently scrub the stone and its setting to remove any dirt or oils that may have accumulated. It is crucial to avoid harsh chemicals and ultrasonic cleaners, as these can damage the gemstone. Peridot should never be exposed to hydrofluoric acid, which can corrode it. After cleaning, rinse the jewelry thoroughly in clean water and dry it with a soft, lint-free cloth.
Storage: When not being worn, Peridot jewelry should be stored separately from other jewelry to prevent scratching. It is advisable to keep it in a soft-lined jewelry box or a fabric pouch. Because of its susceptibility to impact, avoid storing it where it could be knocked or dropped.
Avoiding Damage: It is important to protect Peridot from extreme temperatures and rapid temperature changes, as this can cause internal stress and potentially crack the stone. When wearing Peridot jewelry, it is wise to remove it before engaging in activities that could subject it to hard knocks, such as sports, gardening, or heavy manual work. By following these simple care instructions, a Peridot gemstone can retain its beautiful green luster for many years.
Conclusion
Peridot is a gemstone of remarkable beauty and historical depth. Its unique, vibrant green color, derived from its formation deep within the Earth and brought to the surface by volcanic forces, sets it apart from all other gems. As the primary birthstone for August, it carries a legacy of light, protection, and renewal, cherished from the temples of ancient Egypt to modern jewelry collections. Its journey from a "Gem of the Sun" to a symbol of compassion and abundance highlights its enduring appeal. While moderately durable, its unique properties require mindful care, ensuring that this radiant olive-green gem continues to be a treasured heirloom and a celebrated symbol for generations to come.