Peridot, the vibrant green variety of the mineral olivine, stands as one of the most historically rich and geologically fascinating gemstones in the world. As one of the three modern birthstones for the month of August, it holds a unique place in both ancient lore and contemporary jewelry. Unlike many gemstones that owe their color to trace impurities, peridot’s distinctive hue is an intrinsic part of its chemical makeup, resulting in a singular gem with a storied past. From the ancient Egyptian mines that supplied Cleopatra’s emeralds to modern sources in Arizona, peridot has captivated humanity for millennia. This article explores the complete profile of peridot, from its geological formation and gemological properties to its journey through history and its enduring symbolism.
The significance of peridot extends beyond its role as a birthstone. It is a gem that has been found in meteorites and is believed by some to have been a favorite of ancient pharaohs. Its color, a brilliant olive to lime green, is instantly recognizable and has been the subject of admiration and myth for over three thousand years. While it shares the month of August with spinel and sardonyx, peridot’s unique story sets it apart. This guide will delve into the science behind its formation, the locations where it is mined, its physical characteristics, and the cultural beliefs that have grown around it. For the gem enthusiast, the jewelry buyer, and the student of gemology, understanding peridot means appreciating a gem that is as scientifically significant as it is beautiful.
History and Lore
The history of peridot is deeply intertwined with the civilization of ancient Egypt. The gemstone was famously mined on Zabargad Island, also known as St. John’s Island, in the Red Sea. This location was the primary source of peridot for the ancient world, and its gems were highly prized. The Egyptians referred to peridot as "the gem of the sun," believing it was a gift from the sun god Ra. This association gave the stone a powerful spiritual significance, and it was worn for protection against evil spirits and nightmares. It was believed that peridot could dispel darkness and fear, much like the sun’s rays banish the night.
Cleopatra, the last active ruler of the Ptolemaic Kingdom of Egypt, is famously associated with emeralds. However, historical research and gemological analysis suggest that many of the gems she wore, which were thought to be emeralds, were in fact peridot. The peridot mines of Egypt were so significant that they were operated for centuries under the Pharaohs' rule. The island of Zabargad was treacherous, and the mining conditions were harsh, but the allure of the gem was so strong that it persisted. The gems mined there were often of a large size, and many significant historical artifacts, including church treasures in Europe, feature large peridots that were once believed to be emeralds.
Beyond Egypt, peridot has a rich tapestry of lore. In Hawaiian legend, the gemstone is considered the tears of the goddess Pele, the deity of volcanoes and fire. Each green peridot crystal is said to be a frozen tear that fell from Pele’s eyes as she wept for the life that was destroyed by her volcanic creations. This gives the gem a connection to both creation and destruction, a powerful duality in mythology. In medieval times, peridot was used to make carvings for religious talismans and was believed to have healing properties. It was thought to promote sleep when set in gold and to ward off evil when worn on the left arm.
The journey of peridot to its modern status as a birthstone is a reflection of evolving trends in jewelry and gemology. The first modern list of birthstones was standardized in 1912 by the National Association of Jewelers in the United States. This list has been updated periodically to reflect market availability and popular demand. Sardonyx was the original August birthstone, but peridot was added as a modern alternative due to its beauty and growing popularity. More recently, in 2016, spinel was introduced as a third option for August, giving those born in that month a wider palette of choice. This evolution shows how birthstone lists are not static but adapt to cultural and commercial shifts.
Geological Formation and Sources
Peridot is unique among gemstones because it is formed deep within the Earth's mantle and brought to the surface through tectonic activity and volcanism. Its parent rock is olivine, a common mineral in the upper mantle. Under specific conditions of heat and pressure, olivine crystallizes into the gem-quality green crystals we know as peridot. This formation process is distinct from many other gems, which are typically formed in the Earth's crust. This deep-earth origin is also why peridot is sometimes found in meteorites, making it one of the few gems known to have an extraterrestrial origin. These "space peridots" are extremely rare but provide fascinating evidence of gem formation beyond our planet.
Historically, the most important source of peridot was the island of Zabargad in the Red Sea. This mine, which operated from as early as 1500 B.C. until the early 20th century, produced the majority of the world's peridot. The gems from this location were known for their exceptional quality and size. However, today, the most significant commercial sources of peridot are located in the United States, particularly in Arizona. The San Carlos Apache Reservation in Arizona is a major producer of peridot, supplying a large portion of the global market. The gem is also found in other parts of the United States, including New Mexico and Hawaii.
Other notable sources of peridot are found around the world. Pakistan, particularly the remote region of the Kohistan-Eparchament, is known for producing high-quality peridot with a vibrant green color. Myanmar (Burma) has also been a traditional source of fine peridot. In Australia, peridot is found in New South Wales and Queensland. More recently, a new source was discovered in the late 20th century in the San Carlos Apache Reservation in Arizona, which has become a key supplier of peridot to the global market. These diverse sources ensure a steady supply of this gemstone, though large, high-quality stones remain relatively rare.
The formation and discovery of peridot are a testament to the dynamic geological processes of our planet. Its presence in volcanic rocks and even meteorites makes it a subject of great interest for geologists and gemologists alike. The gem's origins are as deep and complex as the Earth itself, adding to its allure and mystique.
Gemological Properties
Understanding the gemological properties of peridot is essential for appreciating its value and for proper identification. As a member of the silicate mineral group, peridot has a specific chemical formula and a set of physical characteristics that distinguish it from other green gemstones like emerald or tourmaline.
Chemical Composition and Structure: Peridot is the gem variety of the mineral olivine. Its chemical formula is (Mg, Fe)₂SiO₄, indicating it is a magnesium iron silicate. The green color of peridot is directly related to its iron content. Unlike many gemstones, where color is caused by trace impurities, peridot’s color is an inherent feature of its chemical composition. The amount of iron present determines the shade of green, ranging from yellowish-green to a deep olive.
Hardness and Durability: On the Mohs scale of hardness, peridot ranks between 6.5 and 7. This makes it a relatively durable gemstone, suitable for a variety of jewelry applications, including rings, earrings, and pendants. However, its hardness is lower than that of sapphire or ruby (Mohs 9) and diamond (Mohs 10), so it requires some care to avoid scratching. It is also important to note that peridot has poor toughness and is somewhat prone to chipping or cleaving if struck with sufficient force. This is due to its crystal structure, which has directions of weakness. Therefore, protective settings are recommended for peridot jewelry that will be worn daily.
Color and Clarity: The most prized color for peridot is a rich, pure green with no secondary hues. However, peridot is also found in shades of yellowish-green and brownish-green. Large peridot gems, typically over 10 carats, are more likely to exhibit the vibrant green color that is most desired. Smaller stones often have a green color with a slight yellow tint. Peridot is typically transparent with a vitreous (glassy) luster. It is generally "eye-clean," meaning it lacks significant inclusions visible to the naked eye, though some stones may contain small, black specks of mineral inclusions.
Optical Properties: Peridot exhibits strong double refraction, a property where a single ray of light entering the gem is split into two rays. This can be observed with a loupe, as the facets on the back of the stone may appear doubled. This is a key identifying characteristic for peridot. It is also sometimes fluorescent under ultraviolet light, though this is not a primary identification feature.
The following table summarizes the key gemological properties of peridot:
| Property | Description |
|---|---|
| Chemical Formula | (Mg, Fe)₂SiO₄ |
| Mineral Group | Silicate (Olivine) |
| Mohs Hardness | 6.5 - 7 |
| Crystal System | Orthorhombic |
| Refractive Index | 1.65 - 1.69 (Strong Double Refraction) |
| Luster | Vitreous (Glassy) |
| Specific Gravity | 3.34 |
| Typical Inclusions | Small black specks, liquid inclusions, fingerprint inclusions |
Symbolism and Metaphysical Beliefs
Peridot is steeped in a rich history of symbolism and metaphysical beliefs that span across cultures and eras. Its vibrant green color, reminiscent of new growth and the life-giving power of the sun, has made it a powerful symbol of nature, vitality, and protection.
As "the gem of the sun" in ancient Egypt, peridot was believed to possess the power of light. It was thought to bring the wearer joy, good fortune, and protection from evil spirits. The Egyptians mined the gem on Zabargad Island and set it into jewelry that was worn for both adornment and spiritual defense. It was also believed to have healing properties, with ancient physicians using it to treat asthma and other ailments related to the respiratory system.
In Hawaiian culture, the legend of the goddess Pele’s tears imbues peridot with a connection to the powerful forces of nature. It represents both the sorrow of destruction and the beauty that can emerge from it. This symbolism makes peridot a gem of transformation and resilience.
During the Middle Ages, peridot was popular among clergy and nobility. It was used to decorate churches and was believed to have the power to dispel darkness and fear. It was often set in gold and worn on the left arm to ward off evil. Some believed that peridot could help with insomnia when placed under a pillow and that it could improve relationships by calming anger and jealousy.
In modern crystal healing, peridot is associated with the heart chakra and is believed to promote emotional well-being. It is said to attract love, ease jealousy and anger, and bring a sense of peace and happiness. It is also thought to be a stone of abundance, helping its wearer to achieve their goals and manifest wealth. While these metaphysical beliefs are not scientifically proven, they contribute to the enduring popularity and cultural significance of peridot.
Care and Cleaning
Proper care is essential to maintain the beauty and longevity of peridot jewelry. Due to its physical properties, peridot requires more attention than some of the more durable gemstones like sapphire or diamond.
The primary concern for peridot is its relative softness (6.5-7 on the Mohs scale) and poor toughness. This means it can be scratched by harder materials and can chip or crack if it receives a sharp blow. To prevent damage, it is advisable to store peridot jewelry separately from other jewelry pieces, preferably in a soft cloth or a lined jewelry box. When engaging in activities that could subject the gem to impact or abrasion, such as gardening, sports, or heavy housework, it is best to remove peridot jewelry.
Cleaning peridot is relatively straightforward, but it should not be done with harsh chemicals or extreme temperatures. The best method is to use warm, soapy water and a soft brush, such as a toothbrush, to gently scrub the gem and its setting. Rinse thoroughly with clean water to remove any soap residue. Ultrasonic cleaners and steam cleaners are generally not recommended for peridot. The vibrations from an ultrasonic cleaner can cause damage if the stone has any fractures, and the high heat and pressure of a steam cleaner can also be detrimental. After cleaning, pat the jewelry dry with a soft, lint-free cloth.
By following these simple care instructions, a peridot gemstone can remain a vibrant and beautiful piece of jewelry for many years, retaining its symbolic power and geological wonder.
Conclusion
Peridot is a gemstone of remarkable character, offering a unique blend of scientific intrigue, historical depth, and vibrant beauty. Its journey from the depths of the Earth's mantle, its association with the sun god Ra in ancient Egypt, and its status as a cherished modern birthstone for August all contribute to its special place in the world of gemstones. With its distinct chemical composition, which gives it a signature olive-green hue, and its notable gemological properties like strong double refraction, peridot is a gem that fascinates both experts and casual admirers. Whether set in a ring, worn as a pendant, or simply appreciated for its lore, peridot continues to be a symbol of light, nature, and resilience, captivating all who see its brilliant green sparkle.