August is unique among the months of the year in that it boasts not one, not two, but three official birthstones: peridot, sardonyx, and spinel. This triad represents a fascinating evolution in the concept of birthstones, which has its roots in ancient traditions and has evolved significantly over time. Each of these gemstones carries its own distinct history, physical properties, and symbolic meanings, making the August birthstone selection both rich and diverse. This article delves into the origins, geological characteristics, cultural significance, and modern relevance of these three gemstones, offering a comprehensive overview for gemstone enthusiasts, jewelry buyers, and students of gemology.
History and Lore
The concept of birthstones dates back to ancient times, with one of the earliest references found in the High Priest's breastplate described in the biblical Book of Exodus. This breastplate was adorned with twelve stones, representing the twelve tribes of Israel. Over centuries, this idea evolved into a tradition where each month of the year was associated with specific gemstones, believed to carry protective and symbolic powers.
The tradition of linking gemstones to birth months became more formalized in the 15th century, particularly in Poland and Germany, where the practice began to take on a more structured form. These early traditions formed what is now referred to as the "traditional" or "ancient" birthstone lists. However, the modern birthstone list, as we know it today, began to take shape in the 20th century, with the American National Association of Jewelers (now Jewelers of America) playing a key role in standardizing the list.
For August, the "ancient" birthstone was onyx, a gemstone known for its deep, dark hues and historical use in cameos and carvings. However, as the tradition evolved, peridot emerged as the "traditional" birthstone for August, owing to its widespread popularity and distinctive green color. More recently, in 2016, the modern birthstone list was expanded to include spinel, a gemstone that had long been confused with ruby and other red stones but was eventually recognized for its own unique beauty and properties.
This evolution reflects not only changes in the availability and appreciation of certain gemstones but also the growing influence of the global jewelry industry in shaping modern gemstone traditions. Today, August is associated with three distinct stones—peridot, sardonyx, and spinel—each with its own story and significance.
Geological Formation and Sources
Understanding the geological origins of these gemstones provides insight into their rarity, durability, and aesthetic appeal. Each of the three August birthstones forms under different conditions and is found in various parts of the world.
Peridot
Peridot is a variety of the mineral olivine, which is formed deep within the Earth’s mantle. It is brought to the surface through volcanic activity and can also be found in certain types of meteorites, making it one of the few gemstones that have an extraterrestrial origin. The green color of peridot is due to the presence of iron in its chemical composition. The most prized peridot stones are those with a rich, vivid green hue, often described as "apple green" or "evening emerald."
Peridot is relatively abundant, especially in comparison to other gemstones, and is found in several countries, including:
- United States (particularly in Arizona and Hawaii)
- Egypt
- Australia
- Brazil
- India
- Pakistan
Despite its relative availability, high-quality peridot with excellent color and clarity is still valued in the jewelry market.
Sardonyx
Sardonyx is a type of onyx, which is a banded variety of chalcedony, a form of microcrystalline quartz. Chalcedony forms when silica-rich water seeps into rock cavities and deposits tiny crystals over time. The banding in sardonyx is due to variations in the composition of the water and the minerals it carries, resulting in alternating layers of red or brown and white or pale yellow.
Sardonyx has been historically significant in ancient Rome and Egypt, where it was used for cameos and seals. The stone is known for its granular texture, which makes it ideal for carving and polishing. Sardonyx is commonly found in:
- India
- Brazil
- Ethiopia
- Nepal
- Mexico
It is valued not only for its aesthetic appeal but also for its historical and cultural significance.
Spinel
Spinel is a garnet group mineral, though it is chemically and structurally distinct from most other garnets. It forms in metamorphic and igneous rocks, often in association with granite and basalt. Spinel is known for its wide range of colors, including red, pink, blue, green, and even colorless. The most famous spinel color is the "Balas ruby"—a deep red to purplish-red stone that was historically mistaken for ruby.
Spinel is found in:
- Myanmar
- Sri Lanka
- Vietnam
- Madagascar
- Tanzania
In 2016, spinel was officially added to the list of August birthstones, recognizing its beauty, durability, and historical significance. Spinel is relatively hard (with a Mohs hardness of 8), making it suitable for everyday wear in jewelry.
Gemological Properties
To understand the characteristics of each gemstone, it is essential to examine their physical and optical properties, including hardness, refractive index, color, and crystal structure.
Peridot
- Mineral: Olivine
- Color: Yellowish green to deep green, depending on iron content
- Hardness (Mohs): 6.5–7
- Refractive Index: 1.65–1.69
- Birefringence: 0.035–0.038
- Specific Gravity: 3.34
- Crystal System: Orthorhombic
Peridot has a relatively moderate hardness, which makes it suitable for jewelry but less durable than some other gemstones. Its glassy luster and vibrant color make it a popular choice for rings, pendants, and earrings.
Sardonyx
- Mineral: Chalcedony (a form of quartz)
- Color: Banded red, brown, and white
- Hardness (Mohs): 6.5–7
- Refractive Index: 1.53–1.54
- Specific Gravity: 2.58–2.64
- Crystal System: Trigonal
Sardonyx is polished into cabochons rather than being faceted, as its granular texture does not reflect light in the same way as single crystals. It is often used in cameos, beads, and intaglios, where its banding and contrast can be highlighted.
Spinel
- Mineral: Spinel
- Color: Wide range including red, pink, blue, green, and colorless
- Hardness (Mohs): 8
- Refractive Index: 1.718–1.730
- Specific Gravity: 3.6–4.2
- Crystal System: Cubic
Spinel is harder and more durable than peridot and sardonyx, making it an excellent choice for everyday jewelry. Its high refractive index gives it a sparkling luster, often compared to that of ruby or sapphire.
Symbolism and Metaphysical Beliefs
Each of the August birthstones carries its own symbolic meanings and metaphysical properties, which have been attributed to them over centuries of cultural and spiritual tradition.
Peridot
Peridot has long been associated with positive energy, protection, and prosperity. In ancient Egypt, it was known as the "evening emerald" and was believed to have been created from the tears of the sun god, Ra. The ancient Greeks believed that peridot could ward off nightmares and bring calming dreams. In more modern times, peridot is often associated with healing, renewal, and emotional balance.
Sardonyx
Sardonyx has been used as a protective stone in many ancient cultures. It was believed to enhance courage, strength, and willpower. In Roman and Greek traditions, sardonyx was worn by soldiers and warriors to protect them in battle. It is also associated with good fortune and the ability to overcome obstacles.
Spinel
Spinel has been revered as a stone of vitality and emotional stability. In the past, it was mistakenly identified as ruby, and was used in royal regalia and crowns. Spinel is believed to enhance creativity, clarity, and emotional healing. It is also associated with passion and deep emotional connection, making it a popular choice for romantic jewelry.
Care and Cleaning
Proper care is essential to maintaining the beauty and longevity of any gemstone jewelry. The following guidelines are specific to the three August birthstones:
Peridot
- Avoid exposure to harsh chemicals, as peridot is relatively soft and can be easily damaged.
- Clean with warm, soapy water and a soft brush.
- Store separately from harder gemstones to prevent scratches.
Sardonyx
- Avoid ultrasonic cleaners, as they can damage the granular structure of sardonyx.
- Use a soft cloth and mild soap to clean the stone.
- Store in a dry, cool place, away from direct sunlight.
Spinel
- Spinel is more durable and can be cleaned with ultrasonic or steam cleaners.
- Avoid exposure to high heat, as it can affect the color and clarity.
- Store in a jewelry box, preferably with a soft cloth, to prevent scratches.
Conclusion
The three August birthstones—peridot, sardonyx, and spinel—offer a unique and diverse selection for those born in this month. Each gemstone has its own geological origin, historical significance, and symbolic meaning, making them not only beautiful but also deeply meaningful. From the vibrant green of peridot to the banded elegance of sardonyx and the sparkling brilliance of spinel, these stones reflect the richness of gemstone traditions and the evolving appreciation of natural beauty.
Whether worn as jewelry, collectibles, or gifts, these stones serve as a celebration of individuality and heritage, connecting wearers to centuries of cultural and spiritual significance. As the birthstone tradition continues to evolve, the August birthstones stand as a testament to the enduring allure of gemstones and their ability to inspire and transform.