Peridot, a gem celebrated for its distinctive yellowish-green hue, holds a prominent position as a birthstone for the month of August. Often referred to as the “evening emerald” due to its ability to sparkle even in dim light, this gemstone boasts a fascinating history, unique geological origins, and intriguing symbolic associations. While August also recognizes spinel and sardonyx as birthstones, peridot remains the most widely recognized and popular choice. This article will delve into the history, geological formation, gemological properties, and cultural significance of peridot, providing a comprehensive overview of this captivating gem.
History and Lore
The story of peridot is interwoven with historical misidentification and captivating lore. Ancient civilizations often struggled to differentiate peridot from other green gemstones, particularly emerald and topaz. The island of Topazios in the Red Sea, historically believed to be a source of topaz, was in fact a significant source of peridot. This led to the early association of the name “topaz” with the gem we now know as peridot.
References to peridot appear in historical texts, with some scholars suggesting that Cleopatra’s famed emerald collection may have actually consisted largely of peridot. The gem also holds a place in biblical history, with sardonyx and potentially peridot being referenced as stones in the high priest’s breastplate and as foundational stones of Jerusalem. George Frederick Kunz, in his 1913 publication The Curious Lore of Precious Stones, notes the historical confusion between topaz and peridot, stating that the “topaz of the ancients was usually our chrysolite, or peridot.”
Beyond its historical presence, peridot has been valued for its perceived protective qualities. It is traditionally given as a gift to celebrate a 16th wedding anniversary, symbolizing prosperity and happiness.
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 specific shade of green. 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 (Mg,Fe)2SiO4 for practical purposes.
The formation of peridot is often linked to extreme geological conditions. It is found in hardened lava flows, carried from deep within the Earth’s mantle, and even in meteorites originating from outer space. The gem is typically found in granular masses or embedded grains within basic igneous rocks such as basalt and gabbro.
While specific mining locations are not detailed in the provided sources beyond the historical mention of Topazios, the gem’s formation within volcanic rock suggests a global distribution wherever such geological activity has occurred.
Gemological Properties
Peridot exhibits a range of distinct gemological properties that contribute to its unique character. It possesses a distinct cleavage, meaning it breaks along preferred planes, and a conchoidal, or shell-like, fracture. On the Mohs hardness scale, peridot ranges from 6.5 to 7, indicating moderate durability. This means it is susceptible to scratching from harder materials.
The gem’s density is relatively high, with a specific gravity ranging from 3.27 to 3.37, meaning it feels heavier than many other gemstones of similar size. Peridot is transparent, allowing light to pass through, and its color ranges from yellowish-green to greenish-yellow. This color is a key identifying characteristic, often leading to its nickname, “evening emerald.”
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 |
| Transparency | Transparent |
| Color | Yellowish-Green to Greenish-Yellow |
Symbolism and Metaphysical Beliefs
Throughout history, peridot has been imbued with symbolic meaning. While the provided sources do not detail extensive metaphysical beliefs, its association with prosperity, happiness, and protection, particularly as a 16th-anniversary gift, suggests a positive symbolic resonance. The gem’s historical presence in religious contexts, such as the high priest’s breastplate, also hints at a perceived spiritual significance.
The sources highlight the historical confusion surrounding peridot’s identity, with some believing it to be topaz or emerald. This ambiguity may have contributed to the layering of different symbolic meanings over time.
Care and Cleaning
Given its hardness of 6.5 to 7 on the Mohs scale, peridot requires careful handling to avoid scratches. It is advisable to avoid wearing peridot jewelry during strenuous activities or when exposed to abrasive materials.
Cleaning peridot jewelry can be done with warm, soapy water and a soft brush. Avoid harsh chemicals or ultrasonic cleaners, as these can damage the gem. After cleaning, rinse the jewelry thoroughly with clean water and dry it with a soft cloth. Regular cleaning will help maintain the gem’s brilliance and luster.
Conclusion
Peridot, the captivating yellowish-green birthstone of August, offers a rich tapestry of history, geological intrigue, and symbolic meaning. From its ancient misidentification with topaz and emerald to its formation in volcanic lava and even meteorites, peridot’s journey is as fascinating as its radiant color. Its moderate hardness requires careful handling, but with proper care, this “evening emerald” will continue to sparkle and delight for generations. As a symbol of prosperity, happiness, and protection, peridot remains a cherished gemstone for those born in August and a captivating addition to any gem collection.