August Birthstone: Peridot – A Gem of Volcanic Fire and Ancient Sunlight

Peridot, the vibrant olive-green gemstone designated as the birthstone for August, stands apart in the gemological world for its singular origin and distinctive hue. Unlike many colored gemstones that derive their color from trace impurities within a host mineral, peridot is the gem variety of the mineral olivine, a magnesium iron silicate. Its signature color, ranging from yellowish-green to a deep, rich olive, is an intrinsic property of its chemical composition. As a birthstone, it carries the weight of both modern tradition and ancient lore, believed by some to embody the warmth of the sun and the vitality of life. This article explores the history, formation, properties, and cultural significance of peridot, drawing exclusively on documented sources to provide a comprehensive overview for gemstone enthusiasts and collectors.

The journey of peridot from the depths of the Earth to the jeweler’s display case is a story of geological drama. It is one of the few gemstones formed in a single mineral species, and its formation often occurs under extreme conditions, such as in volcanic rock or deep within the Earth’s mantle. Its history is equally dramatic, with records tracing its use back to ancient Egypt, where it was mined on the island of Zabargad and revered as the "gem of the sun." This article will delve into these aspects, examining the scientific characteristics that define peridot, the locations where it is mined, and the beliefs that have surrounded it for millennia. Through a careful analysis of its properties and lore, we can appreciate why this gemstone continues to captivate the imagination and adorn the hands of those born in August.

History and Lore

The historical narrative of peridot is deeply intertwined with the sands of Egypt and the fiery landscapes of volcanic islands. Its most significant ancient source was the island of Zabargad, also known as St. John’s Island, in the Red Sea. This location is frequently cited in gemological literature as the primary source of peridot for the ancient world. The Egyptians mined peridot here as early as the 4th century B.C., and the gemstone was a favorite of the pharaohs. The most famous historical artifact is the "Evening Star of Russia," a large peridot that is believed to have been part of the Russian Crown Jewels, though its origins are debated. Another notable historical piece is the large peridot housed in the German Cathedral in Cologne, Germany, which is thought to have been brought to Europe by the Crusaders.

Peridot's association with the sun is a recurring theme in its lore. The ancient Egyptians called it the "gem of the sun," believing it protected its wearer from the terrors of the night. This belief may be linked to the gem's brilliant glow when exposed to sunlight or candlelight, a phenomenon that has been noted since antiquity. In medieval Europe, peridot was often confused with emerald due to its green color, and many "emeralds" in historical jewelry, such as those in the Treasury of the Three Kings in Cologne Cathedral, have been identified as peridot. This misidentification underscores the gem's long-standing value and beauty.

The journey of peridot to its status as a modern birthstone is a more recent development. The concept of birthstones can be traced back to the breastplate of Aaron described in the Old Testament, which featured twelve stones representing the twelve tribes of Israel. However, the modern list of birthstones was standardized in 1912 by the American National Retail Jewelers Association (now Jewelers of America), which included peridot as the birthstone for August. This list has been updated periodically, but peridot has remained a constant for August, solidifying its place in contemporary jewelry culture.

Geological Formation and Sources

Peridot is unique among gemstones because it is formed in a single mineral species, olivine, which is a common rock-forming mineral. However, the gem-quality peridot crystals are rare and require specific geological conditions to form. The primary sources of peridot are volcanic in origin. It crystallizes from magma deep within the Earth's mantle and is brought to the surface through volcanic activity. This process often occurs in basaltic lava flows, where peridot crystals can be found in pockets or as inclusions in volcanic rock.

The most significant sources of peridot today include: - Pakistan: The Kashmir region, particularly the area around Srinagar, is known for producing some of the finest peridot crystals. These are often found in the high-altitude mountains, where they are mined from igneous rock. - Arizona, USA: The San Carlos Apache Reservation in Arizona is a major commercial source of peridot. The gemstone is mined from volcanic rock and is known for its large sizes and good clarity, though the color can sometimes be lighter than that from other sources. - Myanmar (Burma): The Mogok region in Myanmar is renowned for its gemstones, including peridot. The peridot from this region is often found in alluvial deposits, having been eroded from the host rock and transported by water. - Egypt: While historical mining on Zabargad Island is well-documented, modern production is limited. However, peridot from Egypt is still occasionally mined and is prized for its rich, deep green color. - Other Sources: Peridot is also found in Australia, Brazil, China, Kenya, Mexico, Norway, and Sri Lanka. However, the quality and size of these deposits vary.

The formation of peridot is closely tied to its geological setting. In volcanic regions, peridot can be found in xenoliths—pieces of mantle rock that are carried to the surface by magma. These xenoliths can contain large, gem-quality crystals. In some cases, peridot is also found in meteorites, known as pallasite meteorites, where it crystallized in the vacuum of space. While these meteoritic peridots are scientifically fascinating, they are not typically used in jewelry due to their rarity and the challenges in cutting them.

Gemological Properties

Peridot is a gemstone with a distinct set of physical and optical properties that make it identifiable and desirable. Its most notable characteristic is its color, which ranges from yellowish-green to olive green. The color is caused by the presence of iron in its chemical composition, and it is an intrinsic property of the mineral, not a result of impurities. Unlike emeralds, which often have inclusions, peridot is typically found with fewer inclusions, making it a relatively clean gemstone.

The following table summarizes the key gemological properties of peridot:

Peridot has a hardness of 6.5 to 7.0 on the Mohs scale, making it durable enough for everyday wear in jewelry, but it is softer than sapphire or diamond. It has two directions of poor cleavage, meaning it can chip or break if struck with sufficient force, so it should be protected in settings like rings. Its specific gravity ranges from 3.27 to 3.48, which is relatively high for a gemstone, giving it a noticeable weight when held.

One of the most intriguing properties of peridot is its double refraction, which is visible under magnification. This means that when light enters the gemstone, it splits into two rays, which can cause a slight doubling of the back facets. This is a useful characteristic for gemologists in identifying peridot. Additionally, peridot can exhibit weak to distinct pleochroism, where the gemstone appears to be different colors when viewed from different crystal directions.

Symbolism and Metaphysical Beliefs

Throughout history, peridot has been attributed with a variety of symbolic meanings and metaphysical powers. In ancient Egypt, it was considered a protective stone, believed to ward off evil spirits and bring the wearer good fortune. Its association with the sun led to beliefs that it could harness solar energy, promoting vitality and health. The ancient Romans also valued peridot, calling it "topazius" and using it for decorative purposes.

In medieval Europe, peridot was believed to have healing properties. It was thought to strengthen the eyes, cure asthma, and promote a calm and peaceful mind. Some legends even claimed that peridot could help to dispel depression and anxiety. These beliefs were often tied to the gemstone's color, which is reminiscent of fresh vegetation and growth, symbolizing renewal and life.

In modern crystal healing practices, peridot is often associated with the heart chakra and is believed to promote emotional balance and compassion. It is also thought to attract abundance and prosperity, making it a popular choice for jewelry intended to bring good luck. While these metaphysical beliefs are not supported by scientific evidence, they contribute to the gemstone's cultural appeal and significance.

Care and Cleaning

Due to its hardness and cleavage properties, peridot requires careful handling and maintenance to preserve its beauty. While it is durable enough for most jewelry, it is susceptible to scratches and chips if not treated properly. The following guidelines are recommended for caring for peridot jewelry:

1. Cleaning: Peridot can be cleaned using warm water, a mild soap, and a soft brush. Avoid using harsh chemicals, such as bleach or ammonia, as they can damage the gemstone. Ultrasonic cleaners are generally safe for peridot, but steam cleaning should be avoided, as the high heat and pressure can cause fractures.
2. Storage: Store peridot jewelry separately from other gemstones to prevent scratches. A soft cloth pouch or a lined jewelry box is ideal.
3. Wearing: Avoid exposing peridot to extreme temperatures or sudden temperature changes, which can cause thermal shock. It is also advisable to remove peridot jewelry before engaging in activities that may subject it to impact, such as sports or heavy manual work.
4. Professional Maintenance: Periodically have peridot jewelry inspected by a professional jeweler to check for loose settings or damage. Re-polishing may be necessary over time to restore its luster.

By following these care instructions, peridot jewelry can retain its vibrant color and brilliance for generations.

Conclusion

Peridot, the birthstone of August, is a gemstone of remarkable beauty and historical significance. Its unique formation in volcanic environments and its intrinsic green color make it a standout in the world of colored gemstones. From the ancient mines of Egypt to the modern sources in Pakistan and Arizona, peridot has been prized for its vibrant hue and durability. Its gemological properties, including its hardness, refractive index, and double refraction, make it a fascinating subject for study and a durable choice for jewelry.

The cultural and metaphysical beliefs surrounding peridot add layers of meaning to its physical attributes. Whether viewed as a protective talisman, a symbol of the sun, or a stone of emotional balance, peridot has captured the human imagination for millennia. Its enduring appeal lies in its ability to combine scientific interest with cultural richness, making it a gemstone that continues to be cherished by collectors, jewelers, and those born in August.

Sources

1. TechCrunch: Iran’s internet shutdown is now one of its longest ever as protests continue
2. Villpress: Iran’s internet shutdown now ranks among the longest ever amid ongoing protests
3. The Irish Times: How Iran cut off the internet and Iranians reconnected to the world
4. Cloudflare Blog: Iran protests internet shutdown