August is a month rich in gemstone tradition, with three distinct birthstones representing its legacy: peridot, sardonyx, and spinel. These gemstones are not only beautiful but also steeped in history, lore, and scientific intrigue. Whether you are an avid gemstone collector, a jewelry buyer, or simply curious about the meaning behind these stones, this article offers a comprehensive look at the gemological properties, cultural significance, and practical care of the August birthstones.
Peridot, the most prominent of the three, has long been cherished for its vivid green hue and its unique geological origins. Known as the gem variety of the mineral olivine, peridot is formed under extreme conditions—either within Earth's mantle or carried to the surface by volcanic activity. Some of the finest peridot gems have even traveled to Earth from meteorites, making it one of the few gemstones with an extraterrestrial origin. Sardonyx, on the other hand, is a type of chalcedony with alternating bands of sard and onyx, prized for its ornamental and symbolic qualities. Lastly, spinel—once mistaken for ruby—has gained renewed appreciation in recent years for its brilliance and durability.
This article will explore the origins, properties, symbolism, and care of these three gemstones, offering insight into why they continue to captivate collectors and jewelry lovers alike.
History and Lore
Peridot: The "Gem of the Sun"
Peridot has a long and storied history that dates back thousands of years. Its name derives from the Arabic word faridat, meaning "gem." Ancient civilizations, including the Egyptians and Romans, revered peridot for its vibrant green color and its protective properties. The Egyptians referred to it as the "gem of the sun," while the Romans called it the "evening emerald" because of its visibility in dim light.
One of the most famous historical references to peridot is its presence in the Shrine of the Three Holy Kings in Cologne Cathedral. This shrine, dating back to the 12th century, contains over 200 carats of peridot that were once believed to be emeralds. Similarly, some historians speculate that Cleopatra’s famed emerald collection may have actually been composed of peridot, further highlighting its historical significance.
Peridot has also been used as a protective talisman. In medieval Europe, it was believed to shield the wearer from "terrors of the night" and was often included in priestly jewelry as early as the second century BCE. The gemstone is also associated with the 16th wedding anniversary, making it a meaningful choice for sentimental gifts.
Sardonyx: The Stone of Strength and Protection
Sardonyx, a banded variety of chalcedony composed of alternating layers of sard and onyx, has a history stretching back over 4,000 years. It is one of the oldest known gemstones and was highly valued in ancient civilizations such as Egypt, Greece, and Rome. Sardonyx was particularly popular as a material for carving cameos and signet rings due to its durability and striking color contrast.
In the Roman Empire, sardonyx was believed to offer protection in battle. Soldiers often wore sardonyx rings engraved with images of Mars, the god of war, for strength and courage. The stone is also mentioned in the Old Testament as one of the stones in the High Priest’s breastplate, symbolizing the strength of spiritual life.
In medieval Europe, sardonyx was associated with clear communication and stable relationships. It was believed to bring happiness and promote harmony in marriage and partnerships. Today, it continues to be seen as a symbol of courage and clarity.
Spinel: The Misunderstood Beauty
Spinel has only recently gained recognition as a distinct gemstone, having long been mistaken for ruby, garnet, and even sapphire. The confusion was especially prevalent in historical royal collections, where some red spinels were believed to be rubies. A notable example is the "Black Prince’s Ruby," now known to be a red spinel of exceptional size and quality.
The 2007 discovery of pinkish and orangy red spinel in Tanzania brought renewed attention to the gem. These stones, with their vibrant colors, have captivated gem collectors and jewelry designers alike. Spinel’s popularity has grown steadily as consumers seek alternatives to more traditional gemstones like ruby and sapphire.
In addition to its aesthetic appeal, spinel is known for its durability—ranking 8 on the Mohs scale of hardness—which makes it suitable for everyday wear in rings and other jewelry.
Geological Formation and Sources
Peridot: From Earth's Mantle to Meteorites
Peridot is a gem variety of the mineral olivine, a magnesium iron silicate that forms in Earth's mantle under intense heat and pressure. It is brought to the surface through volcanic activity or carried to Earth by meteorites. This unique origin makes peridot one of the few gemstones that can be found both on Earth and in space.
The most notable terrestrial sources of peridot include the island of Zabargad (formerly known as Topazios) in the Red Sea, which has been mined for over 3,000 years. Other significant sources include China, Pakistan, Tanzania, Vietnam, and the United States. Peridot is also found in unusual locations like Papakolea Beach in Hawaii, where the sands shimmer with a luminous green hue.
Peridot mined on Zabargad is particularly prized for its quality. The island, known for its harsh conditions, earned the ominous names "Island of Death" and "Ophiodes" (meaning "snake island") due to its dangerous environment. Despite these challenges, the peridot from Zabargad remains highly sought after by collectors and jewelers.
In 2005, peridot was discovered in comet dust returned by the Stardust robotic space probe, reinforcing its cosmic origins. Some peridot gems are believed to be up to 4.6 billion years old, making them among the oldest known gemstones.
Sardonyx: Banded Beauty from Around the World
Sardonyx is a type of chalcedony that consists of alternating layers of sard (a reddish-brown to orange chalcedony) and onyx (a white or black chalcedony). This banded pattern makes it ideal for carving and engraving, especially for cameo and intaglio work.
Significant sources of sardonyx include India, where the stone is known for its strong contrast between the layers. Other notable sources include Brazil, Germany, Czechoslovakia, Madagascar, Uruguay, and the United States. India's sardonyx is particularly valued for its vibrant colors and clarity.
Like peridot, sardonyx has been used for centuries in jewelry and religious artifacts. Its durability and affordability have made it a popular choice for rings and pendants. However, it is important to note that some sardonyx available in the market is dyed to enhance its color, especially when the natural contrast between the layers is weak.
Spinel: A Durable and Colorful Gem
Spinel is a silicate mineral that forms in a wide range of colors, including red, pink, orange, yellow, green, blue, and black. Its most famous form is the red spinel, which was often mistaken for ruby in the past. The hardness of spinel (8 on the Mohs scale) makes it highly durable and suitable for everyday wear in rings and bracelets.
The 2007 discovery of pinkish and orangy red spinel in Tanzania marked a turning point in the gem's popularity. These vivid colors have made spinel a favorite among modern jewelers and collectors. Other notable sources of spinel include Myanmar (Burma), Sri Lanka, Afghanistan, and Madagascar.
Spinel is also known for its chemical stability, meaning it is less prone to damage from light or chemicals than some other gemstones. However, high heat can cause some colors of spinel to fade, so care must be taken during jewelry manufacturing or repair.
Gemological Properties
| Gemstone | Color Range | Hardness (Mohs) | Chemical Formula | Refractive Index | Specific Gravity | Common Cuts |
|---|---|---|---|---|---|---|
| Peridot | Yellowish green to greenish yellow | 6.5–7 | (Mg,Fe)₂SiO₄ | 1.653–1.690 | 3.32–4.58 | Round, oval, emerald |
| Sardonyx | Banded (red, white, black) | 6.5–7 | SiO₂ (silicon dioxide) | 1.48–1.53 | 2.58–2.64 | Cameo, cabochon |
| Spinel | Red, pink, orange, yellow, green, blue, black | 8 | MgAl₂O₄ | 1.718–1.735 | 3.90–4.10 | Round, oval, princess |
Peridot
Peridot is known for its vivid green color, which ranges from yellowish green to greenish yellow. This color is due to the presence of iron within the olivine crystal structure. Peridot has a hardness of 6.5–7 on the Mohs scale, making it relatively durable but not as hard as some other gemstones like sapphire or ruby.
One of the unique properties of peridot is its high double refraction. When viewed through the gemstone, you can see two images of each pavilion facet. This optical effect is due to the way light passes through the crystal structure.
Peridot is also known for its unusual behavior in different lighting conditions. Unlike many colored gemstones, peridot retains its color in both daylight and artificial light, making it a reliable choice for jewelry that is worn in various settings.
Sardonyx
Sardonyx is a type of chalcedony with distinct banding of sard and onyx. The sard layers are typically reddish-brown or orange, while the onyx layers are white or black. This banding creates a striking contrast that is ideal for carving and engraving.
Sardonyx has a hardness of 6.5–7 on the Mohs scale, making it suitable for rings and pendants. However, because it is a form of chalcedony, it is often dyed to enhance its color. High heat or harsh chemicals can affect the color of dyed sardonyx, so care must be taken when cleaning or repairing sardonyx jewelry.
Spinel
Spinel is a versatile gemstone that comes in a wide range of colors, including red, pink, orange, yellow, green, blue, and black. The most famous form is the red spinel, which was often mistaken for ruby in the past. Spinel has a hardness of 8 on the Mohs scale, making it highly durable and suitable for everyday wear.
Spinel is also known for its chemical stability. It is not prone to fading or damage from light or chemicals, making it a practical choice for jewelry. However, high heat can cause some colors of spinel to fade, so care must be taken during jewelry manufacturing or repair.
Symbolism and Metaphysical Beliefs
Peridot: Protection and Renewal
Peridot has long been associated with protection and renewal. In ancient times, it was believed to shield the wearer from evil spirits and "terrors of the night." This protective quality made it a popular stone for priests and warriors alike.
Peridot is also associated with renewal and regeneration. Its vibrant green color symbolizes growth and vitality, making it a meaningful choice for those seeking to embrace new beginnings. In modern times, peridot is often given as a gift to celebrate a 16th wedding anniversary.
Sardonyx: Courage and Clarity
Sardonyx is believed to bring courage and clarity to the wearer. It has been used as a protective talisman in many cultures, particularly in ancient Rome, where soldiers wore sardonyx rings engraved with images of Mars for strength in battle.
In addition to its protective qualities, sardonyx is associated with clear communication and stable relationships. It is believed to promote happiness and harmony in marriage and partnerships. Today, sardonyx is still used in jewelry as a symbol of courage and emotional stability.
Spinel: Passion and Vitality
Spinel is associated with passion and vitality. Its vibrant colors, especially red and pink, are often linked to love and energy. Spinel is also believed to bring balance and emotional stability to the wearer.
In some cultures, spinel is considered a lucky stone that enhances creativity and self-expression. Its durability and beauty make it a popular choice for both collectors and jewelry designers.
Care and Cleaning
Peridot
Peridot has a hardness of 6.5–7 on the Mohs scale, making it relatively durable but not as hard as some other gemstones. To maintain its brilliance, peridot should be cleaned with warm, soapy water and a soft-bristle brush. Avoid using ultrasonic or steam cleaners, as these can cause damage if the gemstone has fractures or inclusions.
Peridot should also be stored separately from harder gemstones to prevent scratches. It is best to remove peridot jewelry before engaging in activities that could expose it to impact or abrasion.
Sardonyx
Sardonyx has a hardness of 6.5–7 on the Mohs scale, making it suitable for everyday wear. However, because it is a form of chalcedony, it is often dyed to enhance its color. High heat or harsh chemicals can affect the color of dyed sardonyx, so care must be taken when cleaning or repairing sardonyx jewelry.
To clean sardonyx, use warm, soapy water and a soft-bristle brush. Avoid using ultrasonic or steam cleaners unless you are certain the stone is undyed. Store sardonyx jewelry separately from harder gemstones to prevent scratches.
Spinel
Spinel has a hardness of 8 on the Mohs scale, making it highly durable and suitable for everyday wear. It is also chemically stable, meaning it is not prone to fading or damage from light or chemicals. However, high heat can cause some colors of spinel to fade, so care must be taken during jewelry manufacturing or repair.
To clean spinel, use warm, soapy water and a soft-bristle brush. Ultrasonic and steam cleaners can also be used, but they should be used with caution if the gemstone has fractures or inclusions. Store spinel jewelry separately from harder gemstones to prevent scratches.
Conclusion
The August birthstones—peridot, sardonyx, and spinel—each offer a unique combination of beauty, history, and symbolism. Peridot, with its vibrant green color and extraterrestrial origins, is a gemstone with a truly cosmic connection. Sardonyx, with its banded beauty and ancient legacy, has been cherished for millennia for its protective and stabilizing properties. Spinel, once mistaken for ruby, has emerged as a gemstone in its own right, prized for its durability and stunning colors.
Whether you are drawn to the protective qualities of peridot, the courage-inspiring nature of sardonyx, or the passionate energy of spinel, these gemstones offer a rich tapestry of meaning and history. As August birthstones, they continue to be celebrated for their beauty and significance, making them a perfect choice for jewelry and meaningful gifts.