For those born on August 31st, the designated birthstone is peridot, a gem celebrated for its vibrant green hues and extraordinary origins. Distinguished by its formation under extreme geological conditions—both deep within the Earth and in the vastness of outer space—peridot stands out among colored stones. As the primary gemstone for the end of August, it carries a legacy stretching back millennia, revered by ancient civilizations as the "gem of the sun." This article explores the comprehensive history, geological formation, gemological properties, and symbolism of peridot, drawing upon authoritative sources to provide a complete guide to this luminous green gem.
History and Lore
Peridot is one of the oldest known gemstones, with a documented history that spans over 3,000 years. Its most significant ancient associations originate from Egypt. The Egyptians prized this gem for its bright, sunny green color, which seemed to shimmer with an inner light even in dim conditions. Consequently, they referred to it as the "gem of the sun." Historical records indicate that peridot was mined on the volcanic island of Zabargad (also known as Topazios) in the Red Sea. This island was the primary source of peridot for the ancient world, and its gems were highly coveted by Egyptian pharaohs and other rulers.
The confusion regarding the identity of peridot is a recurring theme in gemological history. Because of its rich green hue, peridot was frequently mistaken for emerald. One of the most famous examples of this confusion lies in the Shrine of the Three Holy Kings in Germany’s Cologne Cathedral. The shrine is decorated with 200 carats of gems that were believed for centuries to be emeralds but are, in fact, peridot. Some historians even speculate that Cleopatra’s famous emerald collection may have actually been comprised of peridot.
During the Middle Ages, peridot gained the moniker "Evening Emerald." This name arose because the gem retains its vivid color and visibility even in dim light, unlike many other gemstones that appear dark under low illumination. The word "peridot" itself is derived from the Arabic faridat, meaning "gem." Historically, peridot was not only valued for its beauty but also for its perceived protective qualities. It was believed to ward off nightmares and bring the wearer happiness and strength.
Geological Formation and Sources
Peridot is a unique mineral known chemically as olivine, specifically the gem variety of this mineral. It is formed under extreme conditions, distinguishing its origin from many other gems. The vast majority of peridot found on Earth’s surface originates from the Earth’s mantle. It is brought to the surface by volcanic activity, often found embedded in hardened lava that carries it from deep within the Earth.
In a truly extraordinary occurrence, peridot is also found in meteorites that have fallen to Earth from outer space. This cosmic origin makes peridot one of the few gems known to exist beyond our planet. The formation process requires high temperatures and pressure, occurring in the Earth's mantle about 20 to 50 miles below the surface. The gem is then transported upward by tectonic activity or volcanic eruptions.
While the island of Zabargad in the Red Sea was the most famous ancient source, modern mining locations vary. The specific geographic coordinates are not detailed in the provided materials, but the sources confirm that the gem's occurrence is linked to both volcanic regions and extraterrestrial deposits.
Gemological Properties
Peridot possesses distinct physical and optical characteristics that define it as a gemstone. Understanding these properties is essential for identification and appreciation.
Chemical Composition and Structure Peridot is the gem variety of the mineral olivine, with a chemical formula of (Mg, Fe)2SiO4. It forms in the orthorhombic crystal system. The color of peridot is determined by the amount of iron present in its chemical structure; higher iron content results in a deeper green, while lower iron content yields a yellowish-green hue.
Color The color of peridot is its most defining feature. It ranges from yellowish-green to greenish-yellow. The most prized color is often described as a rich "grass green" or a vibrant lime-green. Unlike emeralds, which often have inclusions, peridot is known for its relatively clean appearance, though inclusions are common and accepted. The color is consistent and does not change under different light sources, unlike some other gemstones.
Hardness and Durability On the Mohs scale of hardness, peridot ranks between 6.5 and 7. While this makes it a relatively durable gemstone suitable for jewelry, it is softer than sapphire or diamond. Consequently, it requires some care to prevent scratching or abrasion. It does not possess cleavage, which means it is less likely to split along internal planes when struck, but it does have a property called "parting" in some specimens.
Refractive Index and Optical Properties Peridot has a refractive index that typically ranges from 1.654 to 1.690. It exhibits double refraction (birefringence), which can be observed with specialized equipment. It is strongly pleochroic, meaning it can show slightly different colors (yellow, green, or brown) when viewed from different crystal directions.
Comparison of Properties The following table summarizes the key gemological properties of peridot based on the provided sources:
| Property | Description |
|---|---|
| Mineral Name | Olivine (Gem variety) |
| Chemical Formula | (Mg, Fe)2SiO4 |
| Crystal System | Orthorhombic |
| Hardness (Mohs) | 6.5 – 7 |
| Refractive Index | 1.654 – 1.690 |
| Color | Yellowish-green to greenish-yellow |
| Origin | Earth's mantle (volcanic) and meteorites (cosmic) |
Symbolism and Metaphysical Beliefs
Peridot has been attributed with various symbolic meanings and metaphysical powers throughout history. In ancient Egypt, its association with the sun gave it a reputation for vitality and protection. It was believed to hold off evil spirits and protect the wearer from nightmares.
In the context of modern metaphysical beliefs, peridot is often associated with light, renewal, and positivity. It is considered a stone of compassion and is believed to have a calming effect on the wearer. It is said to help release negative patterns and old grudges, promoting forgiveness and opening the heart to new relationships. Some sources also associate peridot with the Heart Chakra, linking it to emotional healing and the ability to attract love.
For those born on August 31st, peridot is viewed as a gem that embodies transformation and light. Its connection to the end of the summer month aligns it with themes of abundance and personal growth. The "Evening Emerald" moniker further cements its symbolism as a beacon of hope and clarity in times of darkness.
Care and Cleaning
Given its gemological properties, peridot requires specific care to maintain its brilliance and integrity.
Hardness Considerations With a hardness of 6.5 to 7, peridot is durable enough for everyday wear but is susceptible to scratching by harder materials. It should be stored separately from diamonds, sapphires, and rubies to avoid abrasion. It is also prone to "parting," which makes it vulnerable to chipping or cracking if struck against a hard surface. Therefore, protective settings (such as bezel settings) are recommended for rings and bracelets.
Cleaning Instructions Peridot can be cleaned using warm, soapy water and a soft brush. Ultrasonic cleaners are generally safe for peridot unless the stone has significant fractures or inclusions. However, steam cleaning is not recommended, as the high heat and sudden temperature changes can damage the gem.
Chemical Sensitivity Peridot is sensitive to rapid temperature changes and harsh chemicals. It should not be exposed to hydrofluoric acid or strong detergents. When wearing peridot jewelry, it is advisable to put it on after applying cosmetics, hairsprays, and perfumes to avoid coating the stone with chemicals that could dull its surface over time.
Conclusion
Peridot remains a gemstone of significant importance and allure, particularly for those born on August 31st. Its rich history, spanning from the mines of ancient Egypt to the cathedrals of medieval Europe, highlights its enduring value. The gem's unique geological origins—born of both the Earth's fiery mantle and the cold expanse of space—add a layer of mystique that few other stones can claim. Defined by its vivid green color, peridot is a gem of light and renewal. Whether valued for its scientific properties, its historical lore, or its symbolic associations with happiness and protection, peridot continues to be a celebrated and cherished member of the gemstone world.