August, the month of summer's peak, is associated with three distinct gemstones: peridot, sardonyx, and spinel. These stones, each with its own unique properties and historical significance, have captivated humans for centuries. From their formation in the Earth’s mantle and meteorites to their roles in ancient traditions and modern jewelry, the August birthstones offer a rich tapestry of geological, cultural, and symbolic significance. This article delves into the properties, origins, symbolism, and care of these three stones, with a special focus on peridot, the most widely recognized of the trio.
History and Lore
The tradition of assigning gemstones to birth months dates back thousands of years. One of the earliest references to birthstones can be found in the biblical account of the breastplate of Aaron, the high priest, which is said to have contained twelve stones representing the twelve tribes of Israel. These ancient stones were believed to hold protective and spiritual powers, a belief that has influenced the development of modern birthstone lore.
For August, sardonyx is considered the original birthstone, with its use dating back over 4,000 years. Sardonyx, a type of chalcedony, has been found in archaeological sites across the ancient world, including Egypt and Mesopotamia. Its banded red and white pattern made it a favored material for signet rings and seals, which were used to mark important documents and personal correspondence.
Peridot, on the other hand, has been known for its beauty and symbolic value since ancient times. It was mined on the Red Sea island of Zabargad (formerly known as Topazios), where it was often confused with emerald due to its vibrant green color. The Romans referred to peridot as the "evening emerald" because of its ability to retain its color under artificial light. The ancient Egyptians believed peridot was a gift of the sun god, calling it the "Gem of the Sun." Some historians even speculate that Cleopatra’s famed emerald collection may have consisted largely of peridots.
Spinel, the newest of the three August birthstones, has a more recent history in gemological recognition. Often mistaken for ruby in the past due to its deep red color, spinel was only identified as a distinct mineral in the 18th century. Today, it is valued as a more affordable alternative to ruby and is gaining popularity among jewelry designers and collectors.
Geological Formation and Sources
Peridot
Peridot is a gem-quality variety of the mineral olivine, composed of magnesium-iron silicates. Its color ranges from yellowish green to deep olive green, with the intensity of the green hue influenced by the amount of iron in the crystal structure. Peridot is unique in that it can be found not only on Earth but also in meteorites and pallasite meteorites—fragments of space rocks that have traveled through the cosmos for billions of years.
The primary sources of peridot include the Red Sea island of Zabargad (Egypt), which has been a known source since at least the 3rd century BCE. Other significant sources are found in the United States, particularly in Arizona and Hawaii, where peridot can be found in volcanic rock formations. Additional mining locations include Burma (Myanmar), Brazil, China, Kenya, Mexico, Pakistan, and Sri Lanka.
Interestingly, peridot has been found in pallasite meteorites, which are believed to be remnants of the cores of asteroids. In 2005, peridot was also discovered in dust samples brought back from the Stardust space probe, which collected material from a comet. This extraterrestrial connection adds a unique dimension to peridot’s geological story, making it one of the few gemstones with a cosmic origin.
Sardonyx
Sardonyx is a type of chalcedony, a microcrystalline variety of quartz. It is characterized by its reddish-brown body color and white banding, which creates a striking contrast. Sardonyx is formed through the deposition of silica-rich solutions in cavities within volcanic rocks, over time creating the banded patterns that make it so distinctive.
Historically, sardonyx was mined in India, but today it is also found in Brazil, Uruguay, the United States, and Germany. The banded patterns of sardonyx have made it a popular material for signet rings and ornamental carvings, especially in ancient cultures that valued the stone for its supposed protective and symbolic properties.
Spinel
Spinel is a mineral composed of magnesium aluminum silicate. It is known for its wide range of colors, including red, pink, orange, blue, and black, with the red variety being the most historically significant. Spinel forms in metamorphic and igneous rocks, particularly in areas where high-temperature conditions allow for the crystallization of its chemical components.
Although spinel has been used in jewelry for centuries, it was only officially recognized as a distinct mineral in the 18th century. Prior to this, it was often mistaken for ruby, especially in royal collections where its vibrant red color was prized. Notable historical examples of spinel include the Black Prince’s Ruby, which is actually a large red spinel set in the Imperial State Crown of the United Kingdom.
Modern spinel sources include Burma (Myanmar), Afghanistan, Tanzania, and Sri Lanka. Its increasing recognition as a distinct and valuable gemstone has led to a resurgence in its popularity among jewelers and collectors.
Gemological Properties
Peridot
| Property | Value |
|---|---|
| Mineral | Olivine |
| Color | Yellowish green to olive green |
| Refractive Index | 1.65 to 1.69 |
| Birefringence | 0.035 to 0.038 |
| Specific Gravity | 3.34 |
| Mohs Hardness | 6.5 to 7 |
| Cut | Typically cut as round, oval, or emerald cut |
| Carat Weight | Typically found in smaller sizes |
Peridot is known for its relatively high refractive index and birefringence, which can cause it to display a double image when viewed through the stone. This optical effect is one of the ways to distinguish peridot from other green gemstones like emerald or topaz. Its hardness of 6.5 to 7 on the Mohs scale makes it durable enough for everyday jewelry, though it is still softer than emerald (7.5 to 8) and ruby or sapphire (9).
Peridot is also unique in that it does not change color under different lighting conditions. Unlike many other colored gemstones, peridot retains the same green color in both natural and artificial light, a feature that has earned it the nickname “evening emerald.”
Sardonyx
| Property | Value |
|---|---|
| Mineral | Chalcedony (a form of quartz) |
| Color | Reddish brown with white banding |
| Specific Gravity | 2.58 to 2.64 |
| Mohs Hardness | 6.5 to 7 |
| Cut | Often carved into cabochons or used in intaglio work |
| Carat Weight | Available in a range of sizes |
Sardonyx is a durable stone, with a hardness similar to peridot. It is typically cut into cabochons or carved into intricate designs, making it a popular choice for signet rings and ornamental objects. Its banded pattern is natural and highly distinctive, making it easy to identify.
Spinel
| Property | Value |
|---|---|
| Mineral | Magnesium aluminum silicate |
| Color | Red, pink, orange, blue, black |
| Refractive Index | 1.718 to 1.725 |
| Specific Gravity | 3.99 to 4.11 |
| Mohs Hardness | 8 |
| Cut | Round, oval, princess, and cushion |
| Carat Weight | Available in a wide range of sizes |
Spinel is a relatively hard gemstone, with a Mohs hardness of 8, making it durable for everyday wear. It is often cut into brilliant shapes like round, oval, or princess to enhance its brilliance and fire. The red variety of spinel, in particular, is highly valued and is often used as an alternative to ruby due to its similar color and higher durability.
Symbolism and Metaphysical Beliefs
Peridot
Peridot has long been associated with positive energy and protection. In ancient times, it was believed to ward off nightmares and negative thoughts, promoting peace and tranquility. The Romans, who called it the "evening emerald," believed that peridot had the power to calm the mind and bring clarity to the soul.
In medieval Europe, peridot was used in priestly jewelry and was often carried as a protective talisman. It was believed to shield the wearer from evil spirits and the "terrors of the night." Today, peridot is still associated with emotional balance and is thought to promote happiness, contentment, and emotional stability.
Peridot is also the gemstone for the 15th or 16th wedding anniversary, depending on the source. It is believed to symbolize growth, prosperity, and the strengthening of love and life.
Sardonyx
Sardonyx has been used in ancient cultures for its protective and symbolic properties. It was believed to bring courage and strength to the wearer and was often used in signet rings as a way to assert authority and individuality. In medieval Europe, sardonyx was associated with the sun and was believed to bring vitality and energy.
The banded pattern of sardonyx was also seen as a symbol of balance and harmony, with the red representing passion and the white representing purity or clarity. This duality made sardonyx a popular stone for those seeking to balance their emotions and actions.
Spinel
Spinel, particularly the red variety, has been associated with courage, vitality, and emotional strength. In ancient times, it was believed to bring protection and good fortune to the wearer. Red spinel, often mistaken for ruby, was used in royal jewelry and was believed to have healing properties, particularly for the heart and circulatory system.
In modern metaphysical beliefs, spinel is thought to promote emotional healing and to help the wearer release negative emotions and fears. It is also believed to enhance creativity and to bring a sense of joy and optimism.
Care and Cleaning
Peridot
Peridot is a relatively durable gemstone, but it is still softer than many other gemstones, so it requires careful handling. To clean peridot, it is best to use a soft cloth and mild soap with warm water. Avoid using ultrasonic or steam cleaners, as these can cause damage to the stone.
When storing peridot jewelry, it should be kept separate from harder gemstones to prevent scratching. Avoid exposing peridot to harsh chemicals, as these can cause discoloration or damage to the surface.
Sardonyx
Sardonyx is a durable stone and can be cleaned with a soft cloth and mild soap. It is safe to use ultrasonic cleaners, though steam cleaning should be avoided as it can cause the stone to crack. Sardonyx should be stored in a dry place, away from other gemstones, to prevent scratching.
Spinel
Spinel is one of the hardest of the August birthstones and is safe to clean with ultrasonic and steam cleaners. A soft cloth and mild soap can also be used for regular cleaning. Spinel should be stored separately from softer gemstones to prevent scratching. It is also safe to expose spinel to light and heat, as it does not fade or change color.
Conclusion
The August birthstones—peridot, sardonyx, and spinel—each carry a unique history, set of properties, and cultural significance. Peridot, with its cosmic origins and timeless beauty, remains the most widely recognized of the three. Sardonyx, the oldest of the August birthstones, has been valued for millennia for its protective and symbolic qualities. Spinel, once mistaken for ruby, has now found its place as a distinct and valuable gemstone.
Whether chosen for their beauty, durability, or symbolic meaning, these gemstones continue to captivate gemstone enthusiasts, jewelry collectors, and those born in the month of August. Understanding their geological origins, historical use, and metaphysical properties allows for a deeper appreciation of their enduring appeal.