Peridot, a gem celebrated for its distinctive yellowish-green to greenish-yellow hues, holds a prominent place in the world of gemstones, particularly as a traditional birthstone for the month of August. Its history is interwoven with tales of mistaken identity, ancient lore, and even extraterrestrial origins, as it has been found in meteorites. While August boasts additional birthstones – spinel and sardonyx – peridot remains the most widely recognized and cherished. This article will delve into the history, geological formation, gemological properties, symbolism, and care of this captivating gem.
History and Lore
The story of peridot is often one of misidentification. Throughout history, this gem has frequently been confused with other green stones, most notably emerald and topaz. The island of Topazios in the Red Sea, from which the name “topaz” is derived, was, in fact, a significant source of peridot. Ancient sources often referred to peridot as topaz, leading to a historical conflation of the two gems.
Some historians speculate that Cleopatra’s famed emerald collection may have largely consisted of peridot, sourced from these ancient deposits. The Shrine of the Three Holy Kings in Cologne Cathedral features 200 carats of gems long believed to be emeralds, but now identified as peridot. This illustrates the enduring appeal and historical significance of peridot, even when mistaken for more prestigious stones.
Sardonyx and topaz are also mentioned in historical texts alongside peridot, with some scholars believing the “topaz” referenced in ancient writings was actually peridot. This interchangeability in naming further complicates the gem’s historical record. Sardonyx, as the original August birthstone, has a history stretching back over 4,000 years, while peridot gained prominence as a traditional choice. More recently, spinel was added as a modern August birthstone in 2016.
Geological Formation and Sources
Peridot is a gem variety of the mineral olivine, with a chemical formula of (Mg,Fe)2SiO4. The ratio of magnesium and iron within the crystal structure determines the intensity of the green hue. Crystals rich in magnesium and poor in iron are known as forsterite, while those with a higher iron content are called fayalite. Gemological classifications utilize the overall formula, regardless of the specific magnesium-to-iron ratio.
The formation of peridot is often linked to extreme geological conditions. It is frequently found in hardened lava flows, carried from deep within the Earth’s mantle. Remarkably, peridot has also been discovered in meteorites, originating from outer space. This extraterrestrial origin adds to the gem’s mystique and unique appeal.
Peridot crystals are often flattened and found as granular masses or embedded grains within basic igneous rocks like basalt and gabbro. The gem exhibits a distinct cleavage and a conchoidal, or shell-like, fracture pattern.
Gemological Properties
Peridot possesses a range of distinct gemological properties that contribute to its beauty and value. On the Mohs hardness scale, peridot ranges from 6.5 to 7, making it moderately durable and suitable for various jewelry applications. Its specific gravity ranges from 3.27 to 3.37, indicating it is a relatively dense gemstone.
Here's a table summarizing key gemological properties:
| Property | Value |
|---|---|
| Chemical Formula | (Mg,Fe)2SiO4 |
| Hardness (Mohs) | 6.5 - 7 |
| Specific Gravity | 3.27 - 3.37 |
| Cleavage | Distinct |
| Fracture | Conchoidal |
| Color | Yellowish-Green to Greenish-Yellow |
The gem’s color, ranging from yellowish-green to greenish-yellow, is its most defining characteristic. This vibrant hue, often described as “evening emerald” due to its ability to shine even in dim light, is a key factor in its desirability.
Symbolism and Metaphysical Beliefs
Throughout history, gemstones have been imbued with symbolic meanings and metaphysical properties. While the provided sources do not detail extensive metaphysical beliefs specifically associated with peridot, the broader context of birthstones suggests a connection to luck, protection, and personal attributes.
August babies are often described as strong-willed, practical, and natural-born leaders. The association with peridot, spinel, and onyx may be seen as enhancing these qualities. Birthstones, in general, are believed to possess properties that bring good fortune and offer protection to those born in their corresponding month.
Peridot is also traditionally given as a gift to celebrate a 16th wedding anniversary, symbolizing prosperity and happiness.
Care and Cleaning
Due to its moderate hardness, peridot requires careful handling and cleaning to maintain its brilliance. It is susceptible to scratches from harder materials and should be stored separately from diamonds and other abrasive gems.
Cleaning peridot is best achieved with warm, soapy water and a soft brush. Avoid harsh chemicals, ultrasonic cleaners, and steam cleaners, as these can damage the gem. After cleaning, rinse thoroughly with clean water and dry with a soft cloth. Regular cleaning will help preserve the gem’s vibrant color and luster.
Conclusion
Peridot, with its captivating green hues and intriguing history, remains a cherished gemstone and a significant birthstone for those born in August. From its ancient origins and frequent misidentification to its unique geological formation and moderate durability, peridot offers a compelling blend of beauty, history, and scientific interest. Whether admired for its aesthetic appeal, its symbolic meaning, or its connection to the cosmos, peridot continues to captivate gemstone enthusiasts and jewelry lovers alike. Its enduring popularity as a traditional August birthstone ensures its place in the world of gemstones for generations to come.