Peridot: The August Birthstone from the Mantle and the Stars

History and Lore: The Gem of the Sun

Peridot has a documented history that spans thousands of years, with its identity often shrouded in confusion due to its visual similarity to other green gems. The word "peridot" is derived from the Arabic term faridat, which simply means "gem." This etymological root hints at the fundamental value placed upon the stone across ancient cultures.

One of the most significant historical narratives surrounding peridot involves its frequent misidentification. The gemstone has been mistaken for emerald throughout history, a confusion that has led to some of the most famous gem collections in the world being re-evaluated. The Shrine of the Three Holy Kings in Germany’s Cologne Cathedral is adorned with 200 carats of gems that were historically believed to be emeralds but are now confirmed to be peridot. Perhaps even more tantalizing is the speculation among historians that Cleopatra’s legendary collection of emeralds may have, in fact, consisted of peridot from Zabargad. This confusion was not limited to emeralds; the Red Sea island of Topazios, a source that gave its name to the gemstone topaz, actually produced peridot.

The ancient world held peridot in high esteem. It appeared in priests’ jewelry as early as the second century BCE and was later incorporated into the chalices and churches of medieval Europe. The stone was not merely decorative; it was believed to possess potent powers. For centuries, peridot was used as a protective talisman, thought to shield the owner from evil spirits and the "terrors of the night." Its symbolism has evolved into more modern interpretations, centering on strength, balance, eternal love, good luck, and happiness. The stone's association with love is highlighted by historical anecdotes, such as Napoleon Bonaparte’s gift of peridot to his beloved Josephine as a symbol of his eternal affection.

Geological Formation and Sources: A Gem of Extreme Origins

Peridot’s origin story is unlike that of almost any other gemstone. It is the yellowish-green to greenish yellow variety of the mineral olivine. While many gems crystallize in the Earth's crust, peridot is formed in the Earth's mantle. The extreme conditions of the mantle, under immense pressure and heat, create this unique silicate mineral.

The gemstone's journey to the surface is equally dramatic. It is frequently found in hardened lava, which acts as a vehicle, carrying the peridot from deep within the Earth’s mantle during volcanic eruptions. This volcanic origin explains its presence in many of the world’s mining locations.

Adding to its mystique is the fact that peridot is one of the only gems to have been discovered in meteorites. These extraterrestrial peridots, which journeyed from outer space, provide tangible evidence of the gemstone's formation in a cosmos beyond our planet. The discovery of peridot on the Moon and even on Mars further solidifies its status as a truly cosmic gem.

While its origins may be extraterrestrial or deep-seated, the primary sources of peridot for the jewelry market are terrestrial. Today, most of the peridot seen in jewelry originates from China, Myanmar (Burma), Pakistan, Tanzania, and Vietnam. The United States is also a notable source, particularly the state of Arizona, which contributes significantly to the global supply.

The oldest recorded source of peridot is the Egyptian island of Zabargad (historically known as Topazios) in the Red Sea. Mining on this island may have begun as early as 340–279 BCE. Despite producing beautiful, highly desirable peridot, the island was known for its harsh conditions and earned ominous names such as the "Island of Death" and Ophiodes ("snake island"). Another famous location, Peridot Beach in Hawaii, is known for its luminous green sands, which are composed largely of peridot fragments washed ashore from volcanic activity.

Gemological Properties

Understanding the physical and chemical characteristics of peridot is essential for gemologists, jewelers, and consumers. As a variety of olivine, peridot has a distinct set of properties that define its appearance and durability.

Chemical and Physical Characteristics

Peridot is composed of magnesium iron silicate, with the chemical formula (Mg, Fe)₂SiO₄. The signature green color of peridot is determined by its iron content. Unlike many other gemstones, peridot does not typically undergo treatments to enhance its color, making its natural hue a primary feature.

Its hardness on the Mohs scale is 6.5 to 7. While this makes peridot a reasonably durable gem suitable for jewelry, it is softer than sapphire or ruby (both at 9) or diamond (10). This relative softness requires that peridot jewelry be handled with a degree of care to avoid scratches and abrasions. Peridot possesses perfect cleavage in two directions, meaning it can be split along specific planes if struck with sufficient force, which is a critical consideration for both cutting and setting the stone.

Optical Properties and Appearance

Peridot is known for its pleochroic nature, meaning it can display different shades of green when viewed from different crystal directions. The gem's refractive index typically falls between 1.65 and 1.69. Its luster is described as vitreous, or glass-like, which gives the stone its brilliant shine when properly cut.

The color range for peridot is relatively narrow, spanning from yellowish-green to greenish yellow. The most prized color is often described as a rich, pure olive green. The visual appeal of peridot is further enhanced by its clarity; it is generally found with fewer inclusions compared to many other colored gemstones.

Comparative Gemological Data

The following table summarizes the key gemological properties of peridot based on standard identification criteria.

Symbolism and Metaphysical Beliefs

Across cultures and eras, peridot has been imbued with a wide range of symbolic meanings and metaphysical beliefs. Its vibrant green color, reminiscent of new growth and nature, has lent itself to associations with life, renewal, and prosperity.

In the modern era, peridot is strongly associated with positive attributes such as love, happiness, good luck, protection, prosperity, success, fame, growth, truth, and dignity. This broad spectrum of positive symbolism makes it a popular gift for various occasions.

Historically, its use as a protective talisman against evil spirits underscores a belief in its power to ward off negativity and harm. This ancient protective quality has evolved into a more general symbolism of good fortune and well-being. The connection to "eternal love," as evidenced by Napoleon’s gift to Josephine, has made peridot a meaningful stone for romantic gestures and celebrations. Its designation as the gem for the 16th wedding anniversary further cements its role in representing enduring relationships and commitment.

The Modern Context: Peridot as the Most Common Birthstone

In contemporary times, peridot holds a unique demographic distinction in the United States. According to data analysis of birth rates, peridot is the most common birthstone in the country. This is not due to a surge in its popularity as a gem choice, but rather a direct result of demographic trends: August is the peak month for births across a majority of states. Consequently, peridot, as August's birthstone, is statistically the most common gem representing the American population.

This commonality, however, does not diminish its appeal. In fact, in several major U.S. cities—including Seattle, Denver, Salt Lake City, and Worcester—peridot is both the most common and the most popular birthstone, indicating a strong regional preference that aligns commonality with consumer desire. While diamond remains the most popular birthstone overall in 20 states, often driven by its perceived rarity and traditional value, peridot’s strong regional presence demonstrates a deep connection between demographic reality and consumer interest.

The modern resurgence in interest in peridot suggests a continued appreciation for its qualities. Its status as the most common birthstone makes it a significant gem in both tradition and contemporary jewelry preferences, reflecting a fascinating interplay between demographics, cultural tradition, and personal style.

Care and Cleaning

Given its gemological properties, peridot requires specific care to maintain its brilliance and integrity. With a hardness of 6.5 to 7 on the Mohs scale, it is susceptible to scratching from harder materials. To prevent damage, peridot jewelry should be stored separately from other gems and precious metals, ideally in a soft cloth or a lined jewelry box.

Cleaning peridot is straightforward but should be done with care. Warm, soapy water and a soft brush are recommended for routine cleaning. It is crucial to avoid harsh chemicals and extreme temperature changes, as these can damage the stone. Ultrasonic cleaners and steam cleaners are generally not advised for peridot, especially if the stone has been fracture-filled or has significant inclusions, as the vibrations and heat could cause damage. After cleaning, the jewelry should be rinsed thoroughly and dried with a soft, lint-free cloth.

Conclusion

Peridot is a gemstone of remarkable duality. It is a jewel of the deep Earth, forged in the mantle, and a visitor from the cosmos, carried to our planet on meteorites. Its history is rich with misidentification, intrigue, and symbolism, linking ancient pharaohs and medieval priests with modern jewelry buyers. Scientifically, it is a distinct mineral, olivine, with a specific set of properties that give it a unique, vibrant green hue.

Today, peridot’s significance is also measured by demographics. As the birthstone for August, the most common birth month in the United States, it holds the title of the nation's most common birthstone. This fact, combined with its deep historical roots, extraterrestrial origins, and enduring symbolism of strength and good fortune, ensures that peridot remains a gemstone of profound importance and lasting appeal.

Sources

1. Peridot: The August Birthstone and America's Most Common Gem
2. Peridot Birthstone
3. August Birthstones: Peridot, Spinel, and Sardonyx