For those born in the eighth month of the year, August offers a unique distinction: it is one of the few months with two modern birthstones. While peridot has long been associated with the month, spinel was officially added in 1912, providing a vibrant and diverse palette for jewelry enthusiasts. This article explores the geological origins, gemological properties, historical significance, and cultural lore of these two captivating gemstones, drawing exclusively from the provided materials to offer a comprehensive guide for gemstone aficionados and collectors.
Historical and Cultural Significance
The tradition of birthstones is deeply rooted in antiquity, often linked to the Biblical Breastplate of Aaron, which featured twelve stones representing the tribes of Israel. Over centuries, these stones were associated with zodiac signs and eventually assigned to specific months. The modern birthstone list was standardized in 1912 by the Jewelers of America (JA), which established the contemporary selections used today. For August, this list includes peridot and spinel, though historical and astrological alternatives such as sardonyx and carnelian also exist.
Peridot: The Gem of the Sun
Peridot has a storied history, particularly in Ancient Egypt, where it was revered as “the gem of the sun.” This green gemstone was intrinsically linked to nature deities and was believed to hold protective properties. According to Hawaiian legend, peridot stones are the tears of the goddess Pele, symbolizing both the destructive and creative forces of nature. Beyond its divine associations, peridot was traditionally thought to protect the wearer from evil, specifically the forces of darkness, and was believed to enhance the healing power of medicinal drugs. This combination of celestial and therapeutic lore has made peridot a gem of both spiritual and physical safeguarding throughout history.
Spinel: The Recent Addition
Spinel’s inclusion as a modern birthstone is relatively recent. Historically, spinel was often mistaken for ruby, leading to its undervaluation and misidentification in royal collections. However, its distinct properties and wide color range have since been recognized. In the context of birthstone lore, spinel is thought to have a calming effect on the wearer. While it lacks the ancient Egyptian pedigree of peridot, its addition to the August birthstone list reflects a broader appreciation for its beauty and durability. The astrological choice for August is carnelian, a stone associated with courage and vitality, though spinel and peridot remain the primary modern selections.
Geological Formation and Sources
Peridot: A Mineral of the Mantle
Peridot is a transparent gem variety of the silicate mineral olivine. Unlike many gemstones that form in the Earth’s crust, peridot is one of the few that can crystallize in the mantle. It is brought to the surface through volcanic activity. The specific conditions required for large, high-quality peridot crystals make such finds rare. While peridot is not generally considered rare, large pure green stones are scarce. The finest peridot often exhibits a vibrant green color with a slight yellow tint in smaller sizes, while larger specimens (10+ carats) tend to display the most sought-after pure green hues.
Spinel: An Oxide Mineral
Spinel is an oxide mineral, distinct from peridot’s silicate composition. It forms in a variety of geological environments, often found in metamorphic rocks and alluvial deposits. Spinel’s durability and color range have made it a valuable gemstone in its own right. The gem can be opaque or transparent and sometimes exhibits fluorescence under ultraviolet light. While spinel occurs in many locations worldwide, the sources for the most prized varieties are not detailed in the provided materials, though its global occurrence is implied.
Gemological Properties
The physical and optical characteristics of peridot and spinel define their value, durability, and suitability for jewelry. The following table summarizes key properties based on the provided sources.
| Property | Peridot | Spinel |
|---|---|---|
| Mineral Group | Silicate (Olivine) | Oxide |
| Mohs Hardness | 6.5 - 7 | 8 |
| Luster | Glassy | Vitreous |
| Transparency | Transparent | Transparent to Opaque |
| Color Range | Light green, yellowish-green, brownish-green | All colors of the rainbow |
| Optical Feature | High double refraction | Can be fluorescent under UV |
| Rarity | Not rare overall; large pure green stones are scarce | Not explicitly stated, but widely available in various colors |
Peridot’s Characteristics
Peridot’s hardness of 6.5 to 7 on the Mohs scale makes it suitable for most jewelry, though it requires reasonable care to avoid scratches. Its high double refraction gives it a distinctive visual effect, and its glassy luster contributes to its appealing appearance. The color spectrum is limited to shades of green, with the most valued being a vibrant green. The presence of yellow or brown tones can affect its desirability and price.
Spinel’s Characteristics
Spinel’s hardness of 8 places it among the more durable gemstones, resistant to scratching and suitable for rings and other frequently worn pieces. Its vitreous luster and potential for fluorescence add to its appeal. The most remarkable feature of spinel is its color diversity, encompassing virtually every hue in the rainbow. This variety offers jewelers and buyers a wide array of choices, from classic reds to rare blues and pinks.
Symbolism and Metaphysical Beliefs
The symbolic meanings attached to peridot and spinel are as varied as their colors. These beliefs, rooted in historical and cultural traditions, continue to influence how the stones are perceived today.
Peridot: Protection and Healing
Peridot’s symbolism is heavily tied to protection and vitality. In Ancient Egypt, it was a talisman against evil and darkness. It was also believed to enhance the efficacy of medicines, bridging the gap between spiritual and physical healing. Hawaiian mythology imbues peridot with the essence of the goddess Pele, linking it to natural forces and emotional resilience. The stone is associated with peace and clarity, thought to guide the wearer through difficult times.
Spinel: Calm and Clarity
Spinel is associated with calming effects, making it a stone for emotional balance and stress reduction. While its lore is less documented than peridot’s, the belief in its soothing properties aligns with its vibrant yet stable appearance. Spinel’s wide color range allows for personal interpretation; for example, blue spinel might be linked to tranquility, while red spinel could symbolize passion and energy.
Care and Cleaning
Given their respective hardness and stability, peridot and spinel require specific care to maintain their beauty.
Peridot Care
With a Mohs hardness of 6.5 to 7, peridot is moderately durable but can be scratched by harder materials. It is also susceptible to thermal shock, meaning sudden temperature changes can cause fractures. Cleaning should be done with warm, soapy water and a soft brush. Avoid ultrasonic cleaners and steam cleaning, as these can damage the stone. Store peridot jewelry separately to prevent scratches from harder gems like diamonds or sapphires.
Spinel Care
Spinel’s hardness of 8 makes it more resistant to scratches and everyday wear. It is generally stable under normal conditions and can be cleaned using warm, soapy water and a soft cloth. While spinel is more durable, it is still advisable to avoid harsh chemicals and extreme temperatures. Its potential fluorescence under UV light is a unique characteristic but does not affect its care regimen.
Market Value and Pricing
The value of peridot and spinel varies significantly based on quality, size, and color. The provided sources offer insights into peridot pricing, while spinel’s value is more generalized.
Peridot Pricing
Peridot prices for a 1-carat stone range from $5 to $600. Good quality specimens typically fall between $50 and $500, with top-quality gems commanding higher prices. The most valuable peridot is a vibrant green, especially in larger sizes. However, the rarity of large pure green stones means that high-quality peridot over 10 carats is both scarce and expensive.
Spinel Pricing
While specific price points for spinel are not provided in the sources, its value is influenced by its color rarity and clarity. For example, certain colors like red spinel (often mistaken for ruby) or vivid blue spinel can be highly valuable. The general trend in the gem market places spinel in a mid-to-high range, depending on its quality and the absence of treatments.
Conclusion
Peridot and spinel, the modern birthstones for August, each offer a distinct blend of beauty, durability, and cultural significance. Peridot, with its ancient Egyptian heritage and protective lore, is a gem of sunlight and healing. Spinel, a more recent addition to the birthstone list, dazzles with its rainbow of colors and calming symbolism. Both stones possess excellent gemological properties—peridot with its unique green hues and spinel with its exceptional hardness—making them cherished choices for jewelry. Whether selected for their historical depth, aesthetic appeal, or metaphysical beliefs, peridot and spinel provide a meaningful connection to the natural world and the traditions of birthstone lore.