August, the eighth month of the year, is a month steeped in historical significance and natural abundance. Named after the Roman Emperor Augustus Caesar, it was originally called Sextilis—a name derived from the Latin for "sixth month," reflecting its position in the early Roman calendar before the Julian reform. The month of August is not only associated with meteor showers, the back-to-school transition, and the height of summer in the Northern Hemisphere, but it also holds a unique place in the world of gemstones. Those born in August are blessed with the most diverse selection of birthstones of any month—no fewer than three: peridot, onyx, and spinel. This article explores these three primary August birthstones, as well as the lesser-known but historically significant stones like alexandrite, carnelian, sardonyx, and diamond, as they were recognized in various ancient and traditional systems.
We will delve into the historical evolution of August birthstones, tracing their symbolic meanings and cultural significance across time. We will also examine their physical and gemological properties, including their chemical composition, hardness, and how they are formed in nature. In addition, we will look at the modern interpretations and uses of these stones in jewelry, as well as practical advice on caring for these gemstones to preserve their beauty and value.
History and Lore
The tradition of birthstones dates back centuries, with roots in biblical and ancient cultural practices. The earliest known reference to birthstones appears in the Book of Exodus (28:17-20), where twelve stones are listed as being set in the breastplate of the High Priest. These were believed to represent the twelve tribes of Israel and were later associated with the zodiac and the months of the year. While this does not directly name August’s modern birthstones, it underscores the long-standing human fascination with linking gemstones to time and identity.
The concept of birthstones as we know it today became more formalized in the 15th and 16th centuries, particularly in Europe and the Middle East. The earliest known list of birthstones by month appeared in a 15th-century manuscript from Germany, where the stones were associated with both astrological signs and months. This tradition continued to evolve over time, with different regions and cultures developing their own interpretations. For example, traditional Hindu and Ayurvedic systems recognized rubies and sapphires as August birthstones, while Russian and Tibetan traditions included alexandrite and diamond.
In the 20th century, the modern birthstone list was standardized, particularly in the United States and the United Kingdom. It was during this period that peridot was officially adopted as the modern birthstone for August, replacing earlier traditional stones such as sardonyx. The transition was influenced by the gemstone industry’s desire to promote peridot, which is relatively abundant and affordable compared to other gemstones.
Despite this modern standardization, the month of August still retains its historical richness, with nine different gemstones having been associated with it at various points in history. These include peridot, onyx, spinel, sardonyx, carnelian, alexandrite, ruby, sapphire, and diamond. This diversity reflects the varied cultural and historical influences that have shaped the August birthstone tradition over time.
For example, carnelian was considered a traditional and ancient Hebrew birthstone for August, known for its connection to the Earth and its power to instill strength and vitality. Sardonyx, on the other hand, was an older U.S. birthstone for August before peridot took over in the 20th century. Alexandrite, a rare and highly prized gemstone, was the old Russian birthstone for August, valued for its mystical properties and chameonic color change.
This historical flexibility in the August birthstone list highlights how regional, cultural, and economic factors have influenced which gemstones were assigned to specific months. In the modern era, with the rise of gemological science and global trade, these traditions have become more uniform, but the underlying richness of the August birthstone heritage remains intact.
Geological Formation and Sources
Understanding the geological origins and sources of August birthstones provides insight into their rarity, value, and aesthetic qualities. Let’s examine the formation and geographic distribution of the three primary modern August birthstones—peridot, onyx, and spinel—as well as the historically significant ones.
Peridot
Peridot is a silicate mineral that belongs to the olivine family. It is composed primarily of magnesium iron silicate, with the chemical formula Mg₁₋ₓFeₓSiO₄, where x varies between 0 and 1. The gemstone's distinctive olive-green color is due to the presence of iron, with the hue becoming more intense as the iron content increases.
Peridot forms in magnesium-rich igneous rocks, particularly in mafic and ultramafic rocks, and is often found in volcanic environments or in metamorphic rocks that have undergone high-pressure transformation. It can also be found in meteorites, making it one of the few gemstones that can originate from extraterrestrial sources.
The primary sources of peridot today include:
- Zambia – Producing some of the finest peridot, especially large, high-quality stones.
- Madagascar – Known for vibrant green peridot, particularly from the Ankazobe and Vatomandry regions.
- Burmah (Myanmar) – Historically a significant source of peridot, especially during the 19th century.
- United States – The San Carlos Apache Reservation in Arizona is a well-known domestic source.
Peridot is relatively hard on the Mohs scale, rating 6.5 to 7, which makes it suitable for everyday wear, though it is more delicate than diamonds or sapphires. Its vitreous luster and translucent to transparent appearance contribute to its popularity in jewelry, especially in earrings, pendants, and rings.
Onyx
Onyx is a type of chalcedony, a microcrystalline variety of quartz. It is composed of silicon dioxide (SiO₂) and is formed through the precipitation of silica-rich solutions in sedimentary rock layers. Onyx is characterized by its parallel bands of color, which are typically black and white, though it can occur in other combinations like red and white, green and white, or multicolored.
The formation of onyx involves slow, layered deposition, often in cavities or fissures within rocks, where mineral-rich water deposits silica over time. This process creates the distinctive striped patterns that onyx is known for.
Historically, onyx has been mined in various parts of the world, including:
- India – A major source of onyx, particularly black onyx, which has been used in cameos and intaglios for centuries.
- Brazil – Produces a wide range of onyx colors and patterns.
- Mexico – Known for green and black onyx.
- Nepal – A source of white and black onyx.
- United States – Onyx is also found in California and Nevada, though it is less commonly mined for gem purposes.
Onyx has a Mohs hardness of 6 to 7, making it suitable for jewelry, particularly in cabochons and beads. It is often polished to a high luster and is favored for its durability and affordability, though it is not as brilliant as other gemstones.
Spinel
Spinel is a oxide mineral with the chemical formula MgAl₂O₄, though it can contain trace amounts of iron, chromium, or magnesium, which affect its color. Unlike other gemstones, spinel is not part of a larger mineral family, but rather a distinct mineral species with a cubic crystal structure.
Spinel forms in metamorphic and igneous rocks, particularly in basaltic and granitic environments. It is often found in pegmatites and marble deposits, and its high refractive index and vitreous luster make it one of the most sparkling gemstones in the world.
Historically, spinel was frequently mistaken for ruby, especially in large, red specimens. Some of the most famous "rubies" in history, such as the "Black Prince’s Ruby" in the British Crown Jewels, are actually spinel.
Modern sources of spinel include:
- Sri Lanka – One of the most well-known sources of red and pink spinel.
- Myanmar (Burma) – Known for producing high-quality red and blue spinel.
- Vietnam – A major source of spinel, particularly pink and orange varieties.
- Tanzania – Produces a range of spinel colors, including blue and violet.
- Madagascar – A growing source of spinel in recent years.
Spinel has a Mohs hardness of 8, which makes it very durable and suitable for all types of jewelry, including rings and bracelets. Its brilliance and clarity are often comparable to diamonds and sapphires, making it a highly desirable gemstone in both antique and modern jewelry.
Gemological Properties
To fully appreciate the August birthstones, it is important to understand their gemological properties, including their hardness, refractive index, color, clarity, and cut. These factors influence not only their aesthetic appeal but also their suitability for different types of jewelry.
Peridot
- Chemical Formula: Mg₁₋ₓFeₓSiO₄
- Hardness (Mohs Scale): 6.5 to 7
- Refractive Index: 1.65 to 1.70
- Color: Olive green (due to iron content)
- Clarity: Often includes inclusions; rarely eye-clean
- Cut: Round, oval, emerald, and princess cuts are common
- Luster: Vitreous
- Transparency: Translucent to transparent
- Special Properties: Occasionally found in meteorites
Peridot is one of the few gemstones that naturally occurs in only one color—olive green. This makes it unique among gemstones, though it can vary in tone from light green to deep, almost blackish-green, depending on the iron content. Its glassy luster and moderate hardness make it a popular choice for earrings and pendants, though it is less suitable for rings due to its relative fragility.
Onyx
- Chemical Formula: SiO₂
- Hardness (Mohs Scale): 6 to 7
- Refractive Index: 1.48 to 1.53
- Color: Typically black and white, but also occurs in red, green, and other combinations
- Clarity: Often opaque; may have inclusions
- Cut: Cabochon, beads, and carved cameos
- Luster: Waxy to greasy
- Transparency: Opaque to translucent
- Special Properties: Banded patterns due to layered deposition
Onyx is a microcrystalline quartz, and its distinctive banding is a result of layered deposition over time. While it is not as brilliant as other gemstones, its durability and affordability make it a popular choice for intaglios, cameos, and beads. Its waxy luster and opaque nature give it a subtle, elegant appearance, particularly when polished to a high shine.
Spinel
- Chemical Formula: MgAl₂O₄
- Hardness (Mohs Scale): 8
- Refractive Index: 1.718
- Color: Available in a wide range of colors, including red, pink, blue, violet, and orange
- Clarity: Often eye-clean, especially in fine-grade specimens
- Cut: Round, oval, cushion, and princess cuts
- Luster: Vitreous
- Transparency: Transparent
- Special Properties: High refractive index and brilliance
Spinel is one of the brightest and most brilliant gemstones in the world. Its high refractive index and excellent clarity make it ideal for rings and pendants, where it can sparkle beautifully under light. The pink and red varieties are particularly popular, though blue and violet spinel is also gaining attention in the fine jewelry market.
Symbolism and Metaphysical Beliefs
The August birthstones have long been associated with symbolic meanings and metaphysical properties, often reflecting the cultural and spiritual beliefs of the societies that revered them. These beliefs vary across time and geography, but they often emphasize strength, protection, and emotional balance.
Peridot
Peridot is often seen as a stone of self-responsibility, forgiveness, and manifestation. It is believed to help individuals take ownership of their lives, release negative emotions, and manifest their goals. In modern metaphysical practices, peridot is also associated with Kundalini energy, helping to awaken spiritual awareness and emotional clarity.
Historically, peridot was used in protective amulets and talismans, particularly in ancient Egypt and medieval Europe. It was thought to ward off nightmares and negative influences, and to promote inner strength and courage. In Ayurvedic and Hindu traditions, peridot is believed to stimulate the base chakra, enhancing vitality and grounding.
Onyx
Onyx is one of the most protective gemstones in the metaphysical tradition. It is believed to absorb negative energy, protect the wearer from harm, and promote emotional stability. Onyx is often used in intaglios and cameos, and its black and white bands are seen as a symbol of balance and duality.
In ancient Rome, onyx was used in cameos and signet rings, where it was believed to enhance willpower and self-control. In modern crystal healing, onyx is associated with the root chakra, helping to ground the energy and restore a sense of security and confidence.
Spinel
Spinel is a stone of rejuvenation, movement, and spiritual awakening. It is believed to open all the chakras, particularly the heart and crown chakras, and to enhance the flow of Kundalini energy. Spinel is also associated with passion, creativity, and emotional transformation.
Historically, spinel was mistaken for ruby, and in medieval Europe, it was considered a stone of nobility and power. In modern crystal healing, spinel is used to stimulate the heart and solar plexus chakras, helping to awaken love, confidence, and personal power.
Care and Cleaning
Proper care and cleaning are essential for maintaining the beauty and longevity of August birthstones. Each gemstone has specific requirements based on its hardness, composition, and sensitivity to heat and chemicals.
Peridot
- Hardness: 6.5 to 7 (moderate)
- Sensitivity: Sensitive to heat and stress, can fracture under high pressure or sudden temperature changes
- Cleaning: Use mild soap and warm water. Avoid steam cleaning and ultrasonic cleaners, which can cause microfractures or damage to the stone
- Storage: Store peridot separately from harder gemstones to prevent scratching
Onyx
- Hardness: 6 to 7 (moderate)
- Sensitivity: Sensitive to abrasion, but generally durable
- Cleaning: Use soft cloths and mild soap. Avoid harsh chemicals and abrasive cleaners, which can damage the surface or polish
- Storage: Store onyx in a soft pouch or padded box to prevent scratches and abrasion
Spinel
- Hardness: 8 (very durable)
- Sensitivity: Generally very stable, but avoid exposure to extreme heat
- Cleaning: Can be cleaned with ultrasonic cleaners, but avoid steam cleaning, which may damage the polish
- Storage: Spinel can be stored with other gemstones, but for maximum protection, it is best to store in a soft pouch or padded box
Conclusion
The August birthstones—peridot, onyx, and spinel—represent a rich and diverse legacy of cultural, historical, and spiritual significance. From the olive-green brilliance of peridot to the protective symbolism of onyx and the sparkling vitality of spinel, these gemstones offer a deep connection to the past and a meaningful presence in the present.
While peridot has become the modern standard for August, the historical gemstones such as sardonyx, carnelian, alexandrite, ruby, sapphire, and diamond reflect the evolving traditions and regional influences that have shaped the birthstone lore over time. These stones continue to inspire awe and admiration, not only for their aesthetic beauty but also for their symbolic and spiritual power.
Whether worn as jewelry, talismans, or spiritual tools, the August birthstones offer a timeless connection to the earth, the cosmos, and the self. Their geological origins, gemological properties, and cultural meanings make them more than just decorative stones—they are testaments to the enduring human fascination with the natural world.