Those born in August are among the most fortunate when it comes to birthstones. This month is uniquely associated with three distinct gemstones—peridot, spinel, and sardonyx—offering a range of colors, meanings, and historical significance. While peridot is the most widely recognized and cherished August birthstone, the inclusion of spinel and sardonyx expands the palette and symbolism available to those celebrating an August birthday. This article delves into the geological, historical, and cultural aspects of these gemstones, drawing from authoritative and well-documented sources.
History and Lore
The history of August birthstones is rich with ancient traditions and cultural significance. Peridot, known as the “gem of the sun,” has been cherished for millennia. Ancient Egyptians, who mined it from the volcanic island of Zabargad (modern-day St. John’s Island in the Red Sea), believed peridot carried the energy of light and renewal. This belief led them to call it the “Evening Emerald” due to its ability to sparkle under both natural and artificial light. The name "peridot" itself is derived from the Arabic word faridat, meaning “gem,” underscoring its historical importance in the region.
Sardonyx, the original August birthstone, has an even longer history, with its use dating back over 4,000 years. Sardonyx is a type of chalcedony that features distinct bands of red and white. It was highly valued in ancient Egypt and Rome, often used in amulets and seals for protection and to ensure success. Sardonyx was also used in the creation of ceremonial and religious artifacts, reflecting its deep spiritual and practical significance.
Spinel, though a relatively newer addition to the August birthstone list, has its own compelling history. Historically mistaken for ruby, spinel was long overlooked as a gemstone of value. The famous “Black Prince’s Ruby” in the British Crown Jewels is, in fact, a spinel. The name spinel comes from the Spanish word espina, meaning “thorn,” a reference to the pointed crystals the mineral often forms. The recognition of spinel as a distinct and valuable gemstone has grown in recent years, making it a popular alternative to ruby for those seeking a vibrant red gemstone.
These three gemstones reflect a fascinating blend of ancient reverence and modern appreciation, offering August-born individuals a range of choices rooted in history and symbolism.
Geological Formation and Sources
Understanding the geological origins of August birthstones provides insight into their rarity, value, and unique characteristics.
Peridot
Peridot is a gem variety of the mineral olivine, with the chemical formula (Mg,Fe)₂SiO₄. It is formed under extreme conditions, typically in silica-deficient rocks such as volcanic basalt. This unique formation process allows peridot to be carried to the Earth’s surface by lava, where it is then mined. Remarkably, peridot is also found in meteorites, particularly in a type known as pallasite meteorites. These extraterrestrial sources, however, are typically too small for jewelry use, making Earth-mined peridot the most valuable and widely used form.
The most significant deposits of high-quality peridot are found in Zabargad Island (Red Sea), Myanmar (Burma), and the United States (Arizona). The presence of iron in peridot gives it its characteristic yellow-green to greenish-yellow color, with the intensity of the color depending on the amount of iron present. Larger stones with a rich, consistent green hue are considered rare and highly prized.
Spinel
Spinel is a distinct mineral with the chemical formula MgAl₂O₄, and it occurs in a wide range of colors due to variations in trace elements. The most famous and valuable is red spinel, which has historically been confused with ruby. Spinel is formed in igneous rocks, particularly in mafic and ultramafic environments, and is often found in metamorphic rocks as well.
Significant sources of spinel include Afghanistan, Myanmar, Sri Lanka, and Tanzania. The versatility of spinel in color—ranging from deep red to pink, blue, and even black—makes it a highly desirable gemstone. The vibrant red spinels from Afghanistan and the cobalt blue spinels from Burma are particularly notable for their clarity and brilliance.
Sardonyx
Sardonyx is a banded variety of chalcedony, a microcrystalline form of quartz. It forms in sedimentary and volcanic rocks and is often found in nodules or veins. The distinct red and white bands in sardonyx are the result of alternating layers of sard (a reddish-brown chalcedony) and onyx (a white or black chalcedony).
Historically, sardonyx was mined in Italy, India, and the Near East, with the Roman Empire being a major user of sardonyx for seals and amulets. Today, notable deposits are found in Brazil and India, where sardonyx is still mined and used in jewelry and ornamental objects.
Gemological Properties
Each of the August birthstones has distinct physical and optical properties that define their appearance, durability, and use in jewelry.
Peridot
- Color: Yellow-green to greenish-yellow (olive-green is the most common)
- Hardness (Mohs scale): 6.5–7
- Refractive Index (RI): 1.65–1.69
- Specific Gravity: 3.3–4.6
- Transparency: Transparent to translucent
- Luster: Vitreous
- Crystal System: Orthorhombic
- Common Cuts: Faceted (round, oval, emerald), cabochon
Peridot is relatively soft compared to other gemstones, which makes it more susceptible to scratches and damage. It is also sensitive to heat and chemicals, requiring special care when cleaning. Despite these considerations, its vibrant color and sparkle make it a popular choice for earrings, pendants, and rings.
Spinel
- Color: Available in a wide range of colors including red, pink, blue, purple, and black
- Hardness (Mohs scale): 8
- Refractive Index (RI): 1.718
- Specific Gravity: 3.6–4.0
- Transparency: Transparent to translucent
- Luster: Vitreous
- Crystal System: Cubic
- Common Cuts: Faceted (round, oval, cushion)
Spinel is harder and more durable than peridot, making it suitable for everyday wear in rings, pendants, and earrings. Its high refractive index gives it a sparkling brilliance, rivaling that of ruby in appearance. Spinel is also heat-resistant and chemically stable, making it easy to clean and maintain.
Sardonyx
- Color: Banded red and white (occasionally black)
- Hardness (Mohs scale): 6.5–7
- Refractive Index (RI): 1.53–1.54
- Specific Gravity: 2.58–2.64
- Transparency: Translucent to opaque
- Luster: Waxy to vitreous
- Crystal System: Trigonal
- Common Cuts: Cabochon, cameo, intaglio
Sardonyx is a relatively soft and opaque gemstone, often used in cameos, intaglios, and seals. It is durable enough for occasional wear but is best suited for jewelry that is not subject to daily impact. Its distinct banded pattern and stone-like texture make it a popular choice for ornamental and symbolic purposes.
The table below summarizes the gemological properties of the three August birthstones:
| Property | Peridot | Spinel | Sardonyx |
|---|---|---|---|
| Color | Yellow-green to greenish-yellow | Red, pink, blue, black | Red and white banded |
| Hardness (Mohs) | 6.5–7 | 8 | 6.5–7 |
| Refractive Index | 1.65–1.69 | 1.718 | 1.53–1.54 |
| Specific Gravity | 3.3–4.6 | 3.6–4.0 | 2.58–2.64 |
| Transparency | Transparent to translucent | Transparent to translucent | Translucent to opaque |
| Luster | Vitreous | Vitreous | Waxy to vitreous |
| Crystal System | Orthorhombic | Cubic | Trigonal |
| Common Cuts | Faceted, cabochon | Faceted | Cabochon, cameo |
Symbolism and Metaphysical Beliefs
The symbolism of the August birthstones is deeply rooted in historical and cultural traditions, with each gemstone associated with specific meanings and powers.
Peridot
Peridot is widely regarded as a stone of protection, prosperity, and renewal. In ancient Egypt, it was believed to ward off negativity and bring abundance. The stone’s connection to the sun and light made it a symbol of renewal and vitality, particularly important during the summer months.
Modern metaphysical beliefs extend these ideas, with peridot often used in healing practices to promote emotional balance and clarity. It is said to help reduce stress, anxiety, and anger, making it a popular stone for those seeking emotional healing. Peridot is also believed to attract wealth and success, aligning with its historical association with prosperity.
Spinel
Spinel is associated with passion, strength, and transformation. The deep red varieties, in particular, are seen as symbols of courage and vitality. In medieval Europe, spinel was used in amulets and talismans to protect the wearer from harm and to enhance their vitality.
Spinel is also believed to have psychic and spiritual properties, with some traditions suggesting it can enhance intuition and open the heart to love. The gemstone is associated with transformation, making it a popular choice for those undergoing personal change or seeking to overcome challenges.
Sardonyx
Sardonyx has long been associated with protection, courage, and success. In ancient times, it was believed to offer protection from evil spirits and to enhance strength and endurance. Roman soldiers carried sardonyx amulets into battle for protection and to ensure victory.
The gemstone is also associated with self-confidence and personal power, making it a popular choice for those seeking to overcome fear and achieve success. Sardonyx is believed to help the wearer maintain focus and determination, particularly in times of adversity.
Care and Cleaning
Given their different physical properties, each of the August birthstones requires specific care to preserve their beauty and integrity.
Peridot
Due to its lower hardness (6.5–7) and sensitivity to heat and chemicals, peridot should be cleaned gently. Use warm water and mild soap with a soft brush to clean the stone, and avoid exposing it to harsh chemicals, steam, or ultrasonic cleaners. Store peridot separately from harder gemstones to prevent scratches.
Spinel
Spinel is more durable than peridot, with a hardness of 8. It can be cleaned using warm water and a soft brush, and is also safe to use in ultrasonic and steam cleaners. Spinel is resistant to heat and chemicals, making it an easy-to-care-for gemstone.
Sardonyx
Sardonyx is relatively soft and opaque, so it should be cleaned gently with warm water and mild soap. Avoid using chemicals or ultrasonic cleaners, as these can dull the stone’s luster. Sardonyx should also be stored separately to prevent damage from harder gemstones.
Conclusion
The August birthstones—peridot, spinel, and sardonyx—offer a rich tapestry of geological, historical, and cultural significance. Each gemstone brings its own unique beauty, meaning, and symbolism, making them a meaningful choice for those born in August. Peridot, with its sun-like energy and protective qualities, is the most widely recognized and cherished. Spinel, with its vibrant colors and historical intrigue, provides a striking alternative to ruby. Sardonyx, with its ancient roots and symbolic power, adds a touch of durability and mystique to the August birthstone collection.
Whether you are drawn to the sparkling green of peridot, the bold red of spinel, or the banded patterns of sardonyx, these gemstones offer a beautiful and meaningful way to celebrate the spirit of August. Their unique properties and rich histories make them not only valuable as gemstones, but also as symbols of protection, prosperity, and personal strength.