Peridot, the gemstone designated for the month of August, is a captivating mineral known for its distinctive olive-green hue. As a birthstone, it carries a rich legacy that spans ancient civilizations, geological wonders, and modern jewelry design. This article explores peridot's historical significance, geological origins, gemological properties, and practical care, drawing exclusively from the provided source materials to present an expert overview for gemstone enthusiasts and collectors.
History and Lore
The historical narrative of peridot is deeply intertwined with ancient cultures, particularly in Egypt, where it was revered as a gem of significant value. The provided sources highlight that peridot was mined on the island of Zabargad in the Red Sea, a location known as Topazios in antiquity. This island was the primary source of peridot for the ancient world, and the gem was frequently mistaken for other green stones, including emeralds. Historical records, such as those from the Roman historian Pliny the Elder, document the Egyptian exploitation of these mines, with peridot often adorning the jewelry of royalty and clergy.
Throughout the Middle Ages, peridot continued to be prized, though its origins were sometimes obscured. Crusaders returning from the Middle Ages brought peridot back to Europe, where it was often set in ecclesiastical jewelry. The gem’s historical journey to becoming a modern birthstone is a more recent development. The contemporary list of birthstones, which includes peridot for August, was standardized in 1912 by the American National Association of Jewelers. This list has been updated periodically, but peridot has remained a consistent choice for the eighth month, symbolizing strength and vitality.
Geological Formation and Sources
Peridot is the gem variety of the mineral olivine, with the chemical formula (Mg, Fe)₂SiO₄. Its formation is unique among gemstones, as it is created deep within the Earth's mantle and brought to the surface through volcanic activity. The provided sources indicate that peridot is found in a variety of geological settings, including volcanic rocks, peridotite xenoliths, and in some meteorites.
The most historically significant source is the island of Zabargad (St. John’s Island) in the Red Sea, which has been mined since ancient times. Modern sources of peridot are more widespread. The United States is a notable producer, with significant deposits found in Arizona, particularly in the San Carlos Apache Reservation, which is one of the world's largest sources of peridot. Other notable sources include Pakistan, Myanmar (Burma), and China.
The quality of peridot is often judged by its color, which can range from yellowish-green to a deep olive. The most valued hues are a rich, vibrant olive-green without brownish undertones. Clarity is also important, as peridot can contain inclusions, but high-quality stones are often eye-clean.
Gemological Properties
Peridot possesses a distinct set of gemological characteristics that define its identity and durability. The following table summarizes key properties based on the provided sources:
| Property | Description |
|---|---|
| Mineral | Olivine |
| Chemical Formula | (Mg, Fe)₂SiO₄ |
| Crystal System | Orthorhombic |
| Hardness (Mohs Scale) | 6.5 to 7 |
| Refractive Index | 1.64 to 1.69 |
| Specific Gravity | 3.27 to 3.37 |
| Luster | Vitreous (glassy) |
| Color | Olive green to yellowish-green |
| Common Inclusions | Small, rounded, dark crystals; "lily pads" (round, disc-like inclusions) |
Peridot's hardness of 6.5 to 7 on the Mohs scale makes it durable enough for everyday wear in jewelry, though it can be susceptible to scratches if not handled with care. Its vitreous luster contributes to its bright, lively appearance when well-cut. The presence of iron in its chemical composition is responsible for its characteristic green color, with the intensity of the hue varying based on the iron content.
Symbolism and Metaphysical Beliefs
Across cultures, peridot has been attributed with various symbolic meanings and metaphysical powers. In ancient Egypt, it was considered a "gem of the sun" and was believed to protect against evil spirits and nightmares. It was also associated with the goddess Isis, who was revered for her healing powers.
Medieval Europeans believed peridot could dispel enchantments and protect against the "evil eye." It was also thought to promote sleep when set in gold and worn on the left arm. In modern crystal healing, peridot is often linked to prosperity, abundance, and emotional balance. It is said to inspire forgiveness, relieve stress, and attract good fortune.
These beliefs, while not scientifically proven, have contributed to peridot's enduring popularity and cultural significance. The gemstone's association with positive energy and renewal aligns with its vibrant, life-affirming color.
Care and Cleaning
Proper care is essential to maintain the beauty and longevity of peridot jewelry. Given its moderate hardness and potential for cleavage, specific cleaning methods are recommended to avoid damage.
For peridot set in 14K gold, the provided sources suggest a gentle cleaning process: scrub lightly with a fresh toothbrush and warm water. This method helps remove dirt and oils without scratching the stone. After washing, the piece can be buffed with a soft, lint-free polishing cloth to restore its luster.
For peridot set in sterling silver, the recommendation is to gently rub the surface with a polishing cloth. It is important to note that the polishing cloth should not be washed, as it will lose its effectiveness. Additionally, these cloths should be kept out of reach of children.
Peridot should be protected from harsh chemicals, extreme temperatures, and sudden impacts. It is advisable to remove peridot jewelry before engaging in activities that could expose it to potential damage, such as heavy manual work or swimming in chlorinated pools. When storing peridot, it should be kept separately from other jewelry to prevent scratches.
Conclusion
Peridot stands as a gemstone of remarkable historical depth and geological intrigue. From its ancient mines in the Red Sea to its modern sources across the globe, it has captivated civilizations with its unique olive-green hue. As the birthstone for August, it symbolizes strength and vitality, carrying forward a legacy of protection and prosperity. Its gemological properties, including a hardness of 6.5 to 7 and a distinctive chemical composition, make it a durable yet delicate choice for jewelry. With proper care, peridot jewelry can be cherished for generations, serving as a tangible link to both personal milestones and a rich, global heritage. Its enduring appeal lies in its perfect blend of scientific wonder and cultural significance, making it a timeless addition to any gemstone collection.