August is graced with a unique selection of birthstones that span a range of colors, histories, and properties. While peridot is most commonly associated with the month of August, it shares its spotlight with spinel and sardonyx—each of which brings its own distinct charm and significance. These gemstones have been treasured across centuries, not only for their beauty but also for their cultural and symbolic importance.
In this article, we will explore the gemological properties of each of these stones, their historical and cultural significance, and how to care for them. Whether you are an August baby, a jewelry collector, or simply curious about these fascinating gems, this guide will provide you with a comprehensive overview.
History and Lore
Peridot: The Ancient Green Gem
Peridot has a long and storied history that dates back to antiquity. Known as the yellowish-green gem variety of the mineral olivine, peridot has been found in meteorites and volcanic rocks. This connection to extraterrestrial and volcanic origins gives peridot a unique and almost mystical allure.
Historically, peridot was often mistaken for other green gems like emerald and topaz. One of the most notable examples of this misidentification is the Shrine of the Three Holy Kings in Cologne Cathedral, where peridot was once thought to be emerald. Similarly, some scholars believe that Cleopatra’s famed emerald collection may have actually been peridot.
The gem’s name comes from the Arabic word faridat, meaning gem. Peridot was highly valued in many ancient and medieval cultures and was believed to bring happiness, healing, and protection. It was also considered a symbol of purity and was often used in religious and ceremonial contexts.
Spinels: A Misunderstood Gem
Spinel is a gemstone that has long been overshadowed by its more famous counterparts, such as ruby and sapphire. However, it is gaining recognition for its beauty and versatility. Spinels come in a wide range of colors, including red, pink, orange, blue, and black.
The confusion between spinel and ruby is particularly well-documented. For centuries, many red spinels were mistaken for rubies and vice versa. It wasn’t until the development of modern gemological techniques that the two could be accurately distinguished. Today, spinel is appreciated for its brilliance and durability, and it has become a popular alternative to ruby, especially in jewelry.
Spinel has also played a role in royal history. Some of the most famous gems in European royal collections are actually spinel. Its vibrant colors and high refractive index make it an excellent choice for both modern and vintage jewelry designs.
Sardonyx: The Stone of Strength and Protection
Sardonyx is an ancient gemstone that has been used for thousands of years. It is a type of onyx that features bands of reddish-brown and white. This banded pattern gives sardonyx a distinctive and elegant appearance.
Sardonyx has a long tradition in both ancient and medieval cultures. It was particularly favored in the Roman Empire, where it was used in signet rings and amulets. The stone was believed to offer protection, strength, and courage. It was also associated with stable relationships and was thought to help foster loyalty and trust.
In addition to its practical uses, sardonyx has been used in religious and spiritual contexts. It has been incorporated into various forms of sacred jewelry and is considered a grounding stone that helps connect the wearer to the earth.
Geological Formation and Sources
Peridot: From Earth's Mantle to the Stars
Peridot is formed under extreme geological conditions, typically in the Earth’s mantle or in meteorites. It is often found in volcanic rocks and can be brought to the surface through volcanic activity. This process gives peridot its unique chemical composition and color.
Peridot is composed of magnesium iron silicate and has a hardness of 6.5 to 7 on the Mohs scale. Its color ranges from yellow-green to deep olive-green, depending on the amount of iron present.
Major sources of peridot include:
- United States (Arizona, New Mexico)
- Sri Lanka
- Brazil
- Zambia
- Nigeria
- Australia
- Russia
Peridot is known for its transparency and luster, and it is often cut into faceted gemstones to enhance its brilliance. Because it is relatively affordable compared to other green gems, peridot is a popular choice for both jewelry and decorative objects.
Spinel: A Versatile and Resilient Gem
Spinel is a mineral composed of magnesium aluminum oxide. It has a hardness of 8 on the Mohs scale, making it one of the more durable birthstones. Its refractive index is also high, giving it a brilliant, glassy luster.
Spinel can be found in a wide range of colors due to the presence of different trace elements. For example, iron produces red spinel, while chromium produces green and pink varieties. This diversity makes spinel a versatile gemstone for jewelry.
Major sources of spinel include:
- Myanmar (Burma)
- Sri Lanka
- Madagascar
- Afghanistan
- Tanzania
- Vietnam
Spinel is often found in metamorphic rocks and is sometimes found alongside ruby and sapphire deposits. Its durability and brilliance make it a desirable gemstone for both everyday wear and special occasions.
Sardonyx: A Grounding and Protective Stone
Sardonyx is a type of chalcedony, which is a form of microcrystalline quartz. It is characterized by its banded appearance, with alternating layers of reddish-brown and white. This banding is what distinguishes sardonyx from other types of onyx.
Sardonyx has a hardness of 6.5 to 7 on the Mohs scale, making it relatively durable but still requiring some care. It is often used in carvings and cameos, as well as in rings and pendants.
Major sources of sardonyx include:
- Brazil
- India
- Russia
- Germany
- United States (Arizona, New Mexico)
Sardonyx is often found in sedimentary and metamorphic rocks. It is typically mined in large deposits and is then cut and polished to reveal its beautiful banding. The stone is often used in vintage-style jewelry and is particularly popular in signet rings.
Gemological Properties
Peridot
| Property | Detail |
|---|---|
| Chemical Formula | (Mg, Fe)₂SiO₄ |
| Color | Yellow-green to deep olive-green |
| Hardness (Mohs) | 6.5 to 7 |
| Refractive Index | 1.65 to 1.70 |
| Specific Gravity | 3.30 to 4.58 |
| Luster | Vitreous (glassy) |
| Cut | Typically faceted |
| Inclusions | Common, often visible |
Peridot is known for its vibrant color and glassy luster. It is often found with visible inclusions, which are not considered flaws but rather characteristics of the stone. Peridot can be found in a range of sizes, from small gemstones to large crystals.
Spinel
| Property | Detail |
|---|---|
| Chemical Formula | MgAl₂O₄ |
| Color | Red, pink, orange, blue, black |
| Hardness (Mohs) | 8 |
| Refractive Index | 1.718 to 1.762 |
| Specific Gravity | 3.60 to 4.00 |
| Luster | Vitreous (glassy) |
| Cut | Often faceted |
| Inclusions | Typically clean |
Spinel is known for its high refractive index and brilliance. It is available in a wide range of colors, and its durability makes it an excellent choice for everyday wear. Spinel is often cut into round brilliant or oval cuts to maximize its fire and brilliance.
Sardonyx
| Property | Detail |
|---|---|
| Chemical Formula | SiO₂ (with iron and other minerals) |
| Color | Banded red, brown, and white |
| Hardness (Mohs) | 6.5 to 7 |
| Refractive Index | 1.48 to 1.53 |
| Specific Gravity | 2.58 to 2.61 |
| Luster | Waxy to vitreous |
| Cut | Typically cabochon or carved |
| Inclusions | Common, often part of the stone's pattern |
Sardonyx is known for its banded appearance and earthy colors. It is often cut into cabochons or carved into cameos and intaglios. The stone has a waxy to vitreous luster and is often used in vintage-style jewelry.
Symbolism and Metaphysical Beliefs
Peridot
Peridot has long been associated with positivity, joy, and abundance. It is believed to promote confidence and help release negative patterns. In some traditions, peridot is considered a heart chakra stone, helping to open the heart to love and healing.
Ancient cultures believed that peridot had protective properties and could ward off nightmares and negative energies. It was also used in amulets and talismans to bring good fortune and prosperity.
Spinel
Spinel is associated with renewal, inspiration, and vitality. It is believed to help restore energy and inspire hope. In some cultures, spinel is considered a stone of vitality and is used to encourage courage and strength.
Spinel is also believed to have grounding properties and is used in meditation and spiritual practices to help connect the wearer to the earth. Its versatility in color makes it a popular choice for those seeking a gemstone that resonates with their personal energy.
Sardonyx
Sardonyx is a stone of protection, strength, and stability. It is believed to offer grounding energy and help the wearer stay centered and focused. Sardonyx is also associated with courage and is used to help overcome fears and challenges.
In some traditions, sardonyx is considered a stone of relationships and is used to foster loyalty, trust, and commitment. It is often used in signet rings and amulets to help strengthen bonds and promote harmony.
Care and Cleaning
Peridot
Peridot is relatively durable but should be handled with care. It has a hardness of 6.5 to 7 on the Mohs scale, making it susceptible to scratches from harder gemstones. Peridot is also prone to breaking if struck with a hard object.
To clean peridot jewelry, use a soft brush and mild soap with warm water. Avoid using ultrasonic cleaners, as they can damage the stone. Store peridot separately from other gemstones to prevent scratches.
Spinel
Spinel is one of the more durable August birthstones, with a hardness of 8 on the Mohs scale. However, it can still be scratched by harder gemstones like diamond and corundum.
Spinel can be cleaned using a soft brush, mild soap, and warm water. Ultrasonic cleaners can also be used, but it is best to avoid harsh chemicals and abrasive materials. Store spinel jewelry separately to avoid scratches.
Sardonyx
Sardonyx is a relatively durable gemstone, with a hardness of 6.5 to 7 on the Mohs scale. However, it is still susceptible to scratches and can be damaged by harsh chemicals.
To clean sardonyx jewelry, use a soft brush and mild soap with warm water. Avoid using ultrasonic cleaners, as they can damage the stone. Store sardonyx separately from other gemstones to prevent scratches.
Conclusion
August’s birthstones—peridot, spinel, and sardonyx—each offer a unique combination of beauty, history, and symbolism. Peridot, with its vibrant green color and ancient origins, is a symbol of joy and abundance. Spinel, known for its versatility and brilliance, is a gemstone that has been gaining recognition for its beauty and durability. Sardonyx, with its banded appearance and grounding properties, has been treasured for thousands of years for its strength and protection.
These gemstones are not only beautiful but also rich in cultural and historical significance. Whether you are drawn to their colors, their properties, or their history, August’s birthstones offer something for everyone.