Peridot, with its distinctive olive-green hue, stands as one of the most intriguing gemstones in the mineral kingdom. Unlike many gems that owe their color to trace impurities, peridot’s color comes from its fundamental chemical composition. As the modern birthstone for August, it offers a vibrant alternative to the traditional options of sardonyx and spinel. This gem is not a relative of the emerald or tourmaline, but a distinct mineral variety of the olivine group, known for its unique formation deep within the Earth and even in the cosmos.
The allure of peridot extends beyond its visual appeal. It is a gem with a rich history, believed by the ancient Egyptians to be "the gem of the sun," and a stone associated with strength, peace, and good fortune. Its geological origins are equally fascinating, with sources ranging from the volcanic landscapes of Arizona to gemstone deposits in Pakistan and Myanmar. This article will explore the multifaceted nature of peridot, from its scientific properties and historical lore to its modern significance as a cherished birthstone.
History and Lore
The history of peridot is as ancient and layered as the Earth's mantle where it forms. Its most significant historical chapter unfolds in Ancient Egypt, a civilization that revered the stone for its radiant glow. The Egyptians did not simply admire peridot for its beauty; they endowed it with divine significance, calling it "the gem of the sun." This name reflects its connection to the sun god, Ra, and the life-giving power he represented. It was believed that peridot could protect its wearer from the terrors of the night, acting as a ward against evil spirits and nightmares. The primary source for these gems during antiquity was the island of Zabargad (now St. John's Island) in the Red Sea, a treacherous and difficult-to-access location that produced some of the finest peridot crystals known to the ancient world.
Peridot's lore is not confined to Egypt. In Hawaiian traditions, the gem holds a celestial and volcanic origin story. Legend states that peridot stones are the tears of the goddess Pele, the fiery deity of volcanoes and fire. This connection gives the gem a powerful, elemental significance, linking its green color to the life-giving forces of nature that emerge from the Earth's core. This narrative underscores the gem's deep-seated connection to the planet's geological processes.
While the modern list of birthstones for August includes both peridot and spinel, the historical record shows a different traditional stone. The primary traditional birthstone for August was sardonyx, a banded variety of chalcedony. Sardonyx, with its alternating layers of sard and onyx, was valued for its durability and was often used for cameos and intaglios. However, peridot has largely eclipsed sardonyx in modern popularity, becoming the quintessential August birthstone due to its unique color and gemological properties. The introduction of spinel as an additional modern birthstone in 2016 by the American Gem Trade Association further expanded the options for those born in August, acknowledging the gem's growing recognition and availability.
Geological Formation and Sources
Peridot possesses one of the most extraordinary origins among all gem-quality minerals. It is a primary crystal of the mineral olivine, a magnesium iron silicate with the chemical formula (Mg, Fe)₂SiO₄. Unlike most gems that crystallize in the Earth's crust, peridot forms much deeper, in the Earth's mantle. The gem material is brought to the surface through violent volcanic activity. These deep-seated crystals are carried upward in magma, often arriving intact within the volcanic rock itself.
The geological journey of peridot does not end with terrestrial volcanoes. Scientists have confirmed the existence of peridot in pallasite meteorites, which are remnants of protoplanets that existed in the early solar system. This cosmic origin means that some peridot crystals are truly ancient, having been formed billions of years ago in the vastness of space before falling to Earth as meteorites. This unique provenance adds a layer of mystique and scientific fascination to the gem.
The primary sources of peridot for the gem and jewelry trade are located in specific regions around the world known for their unique geological conditions. Key mining locations include:
- United States (Arizona): The San Carlos Apache Reservation in Arizona is a major source of peridot, producing gem-quality material from volcanic formations.
- Pakistan: The region around Kohistan in northern Pakistan is renowned for producing large, high-quality peridot crystals, often found in the metamorphic rock of the Himalayas.
- Myanmar (Burma): The Mogok region of Myanmar, famous for its rubies and sapphires, also yields exceptional peridot.
- China: Deposits in the Tianshan region of northwestern China are a significant source of peridot.
- Egypt: While the ancient mines of Zabargad are less productive today, they remain historically significant.
- Other Locations: Smaller deposits are also found in Australia, Brazil, Kenya, Mexico, Norway, Sri Lanka, and South Africa.
These diverse locations contribute to the global supply of peridot, with each region sometimes producing stones with slightly different characteristics in color and clarity.
Gemological Properties
Understanding the gemological properties of peridot is essential for appreciating its value, durability, and unique characteristics. As a member of the olivine group, it has a distinct set of physical and optical properties that differentiate it from other green gemstones like emerald or tourmaline.
Color and Luster The color of peridot is its most defining feature. It ranges from light green, yellowish-green, to a brownish-green. The most prized color is a rich, vibrant olive-green, often described as "lime green." Unlike many other colored gemstones, peridot's color is not caused by trace chemical impurities but by its inherent iron content. The amount of iron present directly influences the hue and saturation of the green. A fascinating optical phenomenon known as "pleochroism" can be observed in some peridot, where the gem appears yellowish-green when viewed along the crystal's short axis and a more pure green along the long axis. Peridot has a vitreous, or glassy, luster, which gives it a bright and appealing surface sheen.
Hardness and Durability On the Mohs scale of hardness, peridot rates between 6.5 and 7. This makes it a reasonably durable gemstone, suitable for a variety of jewelry applications, including rings, pendants, and earrings. However, its hardness is lower than that of stones like sapphire (9), ruby (9), or diamond (10). Consequently, peridot can be susceptible to scratching if worn daily in a ring and knocked against hard surfaces. It also possesses poor toughness due to what gemologists call "perfect cleavage" in two directions. Cleavage is the tendency of a mineral to break along flat, parallel planes of weakness. This means a sharp blow could cause the gem to chip or fracture, so protective settings are recommended for peridot jewelry that will see regular wear.
Clarity and Inclusions Peridot is typically an "eye-clean" gemstone, meaning that inclusions are usually not visible to the naked eye. However, like most natural gems, it is rarely flawless. Common inclusions can include small, lily-pad shaped liquid inclusions, tiny crystals of other minerals (often dark spinel), and needle-like inclusions. The presence and nature of these inclusions, along with the color and size of the stone, are critical factors in determining its quality and value. Larger peridot gems (over 10 carats) are relatively rare and can command high prices, especially if they exhibit the desirable vivid green color with minimal inclusions.
A Note on Hardness and Care The table below, compiled from information in the sources, provides a quick reference for the hardness of peridot compared to other birthstones, illustrating its relative durability.
| Month | Modern Birthstone | Hardness (Mohs Scale) |
|---|---|---|
| January | Garnet | 6.5-7.5 |
| February | Amethyst | 7 |
| March | Aquamarine | 7.5-8 |
| April | Diamond | 10 |
| May | Emerald | 7.5-8 |
| June | Pearl | 2.5-4.5 |
| July | Ruby | 9 |
| August | Peridot | 6.5-7 |
| September | Sapphire | 9 |
| October | Opal | 5.5-6.5 |
| November | Topaz | 8 |
| December | Tanzanite | 6.5-7 |
Symbolism and Metaphysical Beliefs
Throughout history, peridot has been attributed with a wide range of symbolic meanings and metaphysical powers. These beliefs, passed down through cultures and generations, add a layer of intangible value to the gem's physical beauty.
The ancient Egyptians' designation of peridot as "the gem of the sun" is perhaps its most famous association. They believed it possessed protective qualities, capable of warding off evil spirits and nightmares, particularly when set in gold. Its connection to the sun god Ra implied it could bestow vitality, abundance, and good fortune upon its wearer.
In other cultures, peridot's symbolism shifted towards themes of peace, strength, and healing. It is often associated with the heart chakra and is believed to promote emotional balance, easing anger and jealousy while fostering affection and love. Some traditions hold that peridot can heal stress and bring about a sense of tranquility and well-being. Its connection to the heart also extends to physical healing, with historical beliefs that it could aid in issues related to the heart, lungs, and lymphatic system.
The Hawaiian legend of peridot being the tears of the goddess Pele imbues the stone with the power of creation and transformation. As a product of volcanic fire, it is seen as a stone of rebirth and renewal, helping individuals shed old patterns and embrace new beginnings. For those born in August, peridot is said to enhance confidence, assertiveness, and joy, making it a powerful talisman for personal growth and achievement.
Care and Cleaning
Proper care is essential to maintain the beauty and longevity of peridot jewelry. Given its gemological properties, particularly its moderate hardness and cleavage tendencies, peridot requires mindful handling.
Cleaning: * The safest method for cleaning peridot is with warm, soapy water and a soft brush, such as a baby toothbrush. * Gently scrub the gemstone and its setting, paying attention to the areas underneath the stone where dirt can accumulate. * Rinse thoroughly with clean water to remove all soap residue. * Dry the jewelry completely with a soft, lint-free cloth.
What to Avoid: * Ultrasonic Cleaners: Do not use an ultrasonic cleaner, as the intense vibrations can cause existing fractures or inclusions to worsen, potentially damaging the stone. * Steam Cleaners: Avoid steam cleaning, as the high heat and pressure can also be detrimental to peridot. * Harsh Chemicals: Keep peridot away from harsh chemicals, including household cleaners, bleach, and cosmetics. Chemicals can dull the gem's luster and damage its surface. * Sudden Temperature Changes: Avoid exposing peridot to extreme or rapid temperature changes.
Storage and Wear: To prevent scratching and chipping, store peridot jewelry separately from other gemstones, ideally in a soft-lined jewelry box or a fabric pouch. Due to its cleavage, it is best to remove peridot rings before engaging in activities where the stone might be struck or knocked against a hard surface. With proper care, a peridot gemstone can remain a vibrant and beautiful heirloom for generations.
Conclusion
Peridot is a gemstone of remarkable character, defined by its unique olive-green color, its deep-Earth and cosmic origins, and its rich historical narrative. As the principal modern birthstone for August, it offers a compelling choice for those seeking a gem that is both beautiful and symbolically potent. From its ancient status as the "gem of the sun" in Egypt to its modern association with peace and good fortune, peridot has captivated humanity for millennia. Its specific gemological properties, including a hardness of 6.5-7 on the Mohs scale and its characteristic inclusions, make it a gem that requires knowledgeable care but rewards the owner with a unique and vibrant beauty. Whether valued for its geological rarity, its historical lore, or its aesthetic appeal, peridot remains a significant and cherished member of the birthstone family.