For those born in the month of August, the birthstone selection is uniquely rich, offering a choice between three distinct gemstones: Peridot, Spinel, and Sardonyx. While Sardonyx holds historical significance, the modern landscape of August birthstones is dominated by the vibrant green of Peridot and the rainbow-hued versatility of Spinel. Peridot, in particular, carries a legacy steeped in ancient solar worship and volcanic origins, while Spinel offers a durable and colorful alternative that has often been mistaken for other precious stones throughout history. This article delves into the geological formation, gemological properties, historical lore, and market significance of these August gems, providing a detailed resource for enthusiasts, collectors, and prospective buyers.
History and Lore: From the Sun's Gem to the Impostor's Beauty
The history of Peridot is as vivid as its color, tracing back to ancient civilizations that revered it as a divine gift. In Ancient Egypt, Peridot was known as "the gem of the sun." This designation was not merely poetic; it was deeply intertwined with their religious and cultural practices. The Egyptians believed the stone was linked to nature deities and the sun's life-giving power. A significant source of Peridot for the ancient world was the island of Zabargad (now St. John's Island) in the Red Sea, which was mined for over 3,500 years. The gems were so treasured that they were often mistaken for emeralds by Cleopatra’s contemporaries, though modern gemology confirms they were Peridot.
The stone’s lore extends beyond Egypt. In Hawaiian legend, Peridot stones are considered the tears of the goddess Pele, the deity of volcanoes and fire. This connection to volcanic activity is not just mythological but also geological, as Peridot is one of the few gemstones formed in the mantle and brought to the surface by volcanic activity. Throughout the Middle Ages, Peridot was used to adorn churches and religious artifacts, valued for its clarity and color. The word "Peridot" itself descends from the Medieval Latin peridotus, which may have referred to the gem or to other green stones of similar hue. Another possible etymon is the Arabic faridat, meaning "gemstone," highlighting its universal recognition as a precious find.
In contrast, Spinel’s history is one of mistaken identity and eventual recognition. For centuries, many of the world’s most famous "rubies" were actually red Spinel. The Black Prince’s Ruby, part of the British Crown Jewels, and the Timur Ruby are prime examples. These stones were not properly identified as Spinel until advances in gemological science in the 18th and 19th centuries. The name "Spinel" is derived from the Latin word spina, meaning "thorn," likely referring to the sharp crystals in which it often forms. While Spinel lacks the same ancient solar mythology as Peridot, its journey from being a prized but misidentified gem to a celebrated birthstone in its own right is a fascinating chapter in gemological history. The adoption of a standardized birthstone list by the American National Retail Jeweler’s Association (now Jewelers of America) in 1912 helped solidify Spinel’s place as an August birthstone, alongside Peridot and Sardonyx.
Geological Formation and Sources
Understanding the genesis of these gems provides insight into their unique characteristics and value. Peridot is a transparent gem variety of the silicate mineral group olivine. Its formation is particularly intriguing because it is one of the few gems that crystallizes deep within the Earth's mantle. It is then brought to the surface by volcanic activity, often found in basaltic lavas and peridotite xenoliths. This volcanic origin explains its association with fire and the sun in various cultures. The most significant sources of Peridot include Pakistan, which is known for producing large, high-quality crystals; Arizona in the United States (notably the Four Peaks Mine); and Myanmar. While Peridot is not considered rare in general, large, pure green stones of gem quality are scarce, making them more valuable.
Spinel, an oxide mineral, forms under similar high-temperature and low-pressure conditions, often in metamorphic rocks and alluvial deposits. It is found in a variety of geological settings, including marble and granulite facies. Major sources for Spinel include Myanmar (Burma), Sri Lanka, Thailand, and Vietnam. The gem’s ability to form in a wide array of colors has made it a versatile find for miners. Unlike Peridot, Spinel does not have a singular legendary source like Zabargad, but its presence in the gem-rich regions of Southeast Asia has ensured a steady supply of quality material.
Gemological Properties: A Scientific Profile
For gemologists and buyers, the physical properties of a stone are paramount. These properties determine durability, suitability for different jewelry types, and overall value. The following table summarizes key gemological data for Peridot and Spinel based on available information.
| Property | Peridot (August - Modern) | Spinel (August - Modern) |
|---|---|---|
| Mineral Group | Olivine (Silicate) | Oxide |
| Chemical Formula | (Mg, Fe)₂SiO₄ | MgAl₂O₄ |
| Crystal System | Orthorhombic | Cubic |
| Mohs Hardness | 6.5 - 7 | 8 |
| Refractive Index | 1.635 - 1.690 | 1.718 (approx.) |
| Luster | Vitreous (Glassy) | Vitreous |
| Optical Character | Biaxial (+) | Isotropic |
| Specific Gravity | 3.27 - 4.37 | 3.58 - 3.61 |
| Transparency | Transparent to translucent | Opaque to transparent |
| Color Range | Light green, yellowish-green, brownish-green | All colors of the rainbow, plus black |
Color and Clarity: Peridot’s color is its defining feature, ranging from light green to yellowish-green and brownish-green. The most prized specimens exhibit a vibrant green color, though stones with a slight yellow tint are often considered the best in smaller sizes. Peridot is typically found with good clarity, though inclusions are common. Spinel boasts an extraordinary color palette, encompassing every hue in the rainbow, including the coveted red, blue, pink, and violet shades. It can also be found in black. Spinel can be transparent or opaque, and some varieties exhibit fluorescence under ultraviolet light.
Durability and Suitability for Jewelry: Durability is a critical factor for jewelry, especially for items worn daily like engagement rings or bracelets. According to gemological sources, Peridot has a Mohs hardness of 6.5-7. This places it in the "Fair to Poor" category for durability in some contexts, as it is prone to breakage. While it can be set in rings, extra care is needed to protect it from impacts and abrasion. It is more suitable for earrings, pendants, and occasional-wear rings.
Spinel, with a Mohs hardness of 8, is significantly more durable. It falls into the "Very Good" category for durability, making it suitable for any type of jewelry, including rings and bracelets, with proper care. Its high hardness means it is resistant to scratching and abrasion from everyday activities. This durability, combined with its stunning color range, makes Spinel an excellent and often overlooked choice for fine jewelry.
Symbolism and Metaphysical Beliefs
The symbolic meanings attached to gemstones often enhance their appeal. Peridot, as "the gem of the sun," is historically associated with light, clarity, and vitality. In ancient Egypt, it was linked to the sun god Ra and nature deities, symbolizing rebirth and the cycle of life. Hawaiian legend attributes it to the goddess Pele, imbuing it with the power of volcanic creation and destruction. These connections make Peridot a stone of transformation and growth.
Spinel’s metaphysical beliefs are less documented in ancient texts but are embraced in modern crystal healing practices. Different colors of Spinel are believed to carry different energies. For example, red Spinel is associated with passion and vitality, while blue Spinel is linked to calm and communication. However, it is important to note that these metaphysical beliefs are not supported by scientific gemological data and are considered alternative spiritual practices. The primary value of Spinel in the context of this article is its physical beauty and durability.
Care and Cleaning
Proper care is essential to maintain the beauty and longevity of any gemstone. The cleaning methods depend largely on the stone's hardness and stability.
Peridot: Given its moderate hardness (6.5-7), Peridot requires gentle handling. It should be cleaned using warm, soapy water and a soft brush. Avoid ultrasonic cleaners and steam cleaning, as the vibrations and heat can cause fractures or damage, especially in stones with inclusions. It is also advisable to store Peridot separately from harder gems to prevent scratching.
Spinel: Spinel is much more resilient due to its hardness of 8. It can be safely cleaned with warm, soapy water and a soft brush. It is generally safe for ultrasonic cleaning, but caution is still advised if the stone has significant inclusions or fractures. As with any gemstone, it is best to avoid harsh chemicals and sudden temperature changes.
Market Value and Considerations
The market for August birthstones varies widely based on quality, size, and origin. Peridot prices can range dramatically. For a 1-carat stone, prices can span from $5 to $600. Good quality specimens typically fall between $50 and $500, while top-quality, large, and vibrantly green gems command higher prices. The rarity of large, pure green Peridot contributes to its value.
Spinel’s value has been historically underestimated due to its frequent misidentification as ruby. However, in recent decades, fine Spinel has gained recognition and appreciation in the gem market. Prices for Spinel are highly variable, dependent on color, clarity, and size. The finest red Spinels, for instance, can rival the price of fine rubies, while other colors may be more accessible. The gem’s durability and wide color range make it an attractive option for jewelry designers and collectors seeking value and beauty.
Conclusion
The August birthstones of Peridot and Spinel offer a compelling study in contrasts. Peridot, with its ancient solar heritage and volcanic origins, is a gem of historical depth and vibrant green color. Its moderate hardness requires careful consideration for jewelry use, but its unique color and lore make it a cherished choice. Spinel, on the other hand, is a testament to resilience and versatility. With its exceptional hardness and a spectrum of colors that rivals any gemstone, it is a durable and beautiful option that has finally stepped out of the shadow of mistaken identity. Together, these gems provide August-born individuals with a rich selection, each carrying its own story of formation, history, and symbolic meaning. Whether drawn to the sun-kissed green of Peridot or the radiant palette of Spinel, one is selecting a gemstone with a distinct place in the geological and cultural tapestry of our world.