The August Birthstones: Peridot, Sardonyx, and Spinel – A Journey Through History, Geology, and Symbolism

August is one of the few months that boasts three official birthstones: peridot, sardonyx, and spinel. These gems not only offer a wide array of colors and styles but also carry rich historical and cultural significance. While peridot is the most widely recognized among the three, sardonyx and spinel have each played a unique role in the story of August’s birthstone tradition. This article explores the history, geology, symbolism, and practical care of these stones, providing a comprehensive overview for gemstone enthusiasts, jewelry buyers, and students of gemology.

Introduction

The August birthstones—peridot, sardonyx, and spinel—represent a fascinating intersection of natural beauty, ancient tradition, and modern appreciation. These gemstones have been cherished for millennia, with sardonyx being the original August birthstone and spinel being added more recently in 2016. Peridot, with its vibrant green hues, is the most popular and recognizable among the three. Each of these stones has its own unique properties, symbolic meanings, and cultural associations, making them a rich subject for exploration in the field of gemology.

The origins of the birthstone tradition are rooted in ancient times, with some sources tracing it back to the breastplate of the high priest in the Old Testament, where it is believed that each stone represented one of the twelve tribes of Israel. While modern birthstones differ from these ancient associations, the concept has endured and evolved over time. For August, the inclusion of three distinct gemstones reflects both historical tradition and the evolving preferences of the jewelry industry and consumers.

In this article, we will examine the geological properties, historical significance, cultural symbolism, and care instructions for each of the August birthstones. We will also explore how these stones have been used in jewelry and what makes them valuable choices for those born in August or for those seeking meaningful gemstone gifts.

History and Lore

Sardonyx – The Ancient August Birthstone

Sardonyx is the oldest of the August birthstones, with a history that dates back more than 4,000 years. It is a banded agate, composed of alternating layers of sard, a reddish-brown chalcedony, and onyx, a black or white chalcedony. This banding gives the stone a distinctive and ornate appearance. Sardonyx has been used in jewelry, amulets, and religious artifacts across various cultures, particularly in ancient Egypt and Mesopotamia. It was believed to offer protection and was often carved into seals and talismans. In medieval Europe, sardonyx was associated with courage and was said to help warriors in battle.

Peridot – The "Gem of the Sun"

Peridot has a long and storied history, often being mistaken for other green gems such as topaz and emerald. It is the yellowish green to greenish yellow gem variety of the mineral olivine. The Red Sea island of Topazios, from which the name "topaz" is derived, was historically known for its peridot deposits, not topaz. This explains why peridot was frequently confused with topaz in ancient times.

Peridot has been revered for its beauty and supposed healing properties. The Egyptians referred to it as the "gem of the Sun" and believed it possessed special powers. In ancient Egypt, peridot was used to decorate temples and royal tombs. It was also said to be brought to Earth by shooting stars, as it has been found in volcanic lava in Hawaii and even in meteorites.

One of the most famous historical uses of peridot is in the Shrine of the Three Holy Kings in Cologne Cathedral, Germany. This shrine is adorned with 200 carats of gems that were once thought to be emeralds but are actually peridots. Some historians speculate that Cleopatra’s famed emerald collection may have also been composed of peridot.

Spinel – The Modern August Birthstone

Spinel is the newest addition to the August birthstone list, having been officially recognized in 2016. For centuries, red spinel was often mistaken for ruby, and in some cases, even sold as such in royal courts and jewelry collections. This misidentification was due to the similar color and appearance of the two stones, but spinel has distinct optical and chemical properties that differentiate it from ruby.

The rediscovery of spinel’s unique qualities has led to a resurgence in its popularity, especially among consumers seeking a more affordable alternative to ruby. Spinel comes in a variety of colors, but the most common shades associated with August are pink and red. Its versatility, brilliance, and durability make it a valuable and elegant choice for modern jewelry.

Geological Formation and Sources

Peridot: A Gem Born from Fire

Peridot is formed under intense heat and pressure, typically deep within the Earth's mantle, and is brought to the surface through volcanic activity. It is also found in meteorites, making it one of the few gemstones that originate from outer space. This cosmic origin adds to the mystique and allure of peridot.

The finest quality peridot is found in Arizona, USA, particularly in the Bullfrog Mine, which is known for producing high-quality, vibrant green peridots. Other notable sources include Sri Lanka, Egypt, Madagascar, and Brazil. These deposits are often located in basaltic rock formations, where the stone can be found in lava flows and impact craters.

Peridot’s color is influenced by the amount of iron it contains. The more iron present, the deeper the green hue. The most desirable peridots are those with a vibrant green color and minimal brown or yellow tones.

Sardonyx: A Stone of Strata

Sardonyx is a banded agate, formed through the precipitation of silica-rich water in rock cavities. The banding is created by alternating layers of sard and onyx, which give the stone its characteristic striped appearance. This process occurs over thousands of years, with each layer forming under different environmental conditions.

Sardonyx is primarily found in India, Brazil, and Mexico, where it is mined from volcanic rock formations. The oldest known sardonyx comes from Egypt, where it was used in ancient jewelry and amulets. The stone was also highly valued in Rome, where it was carved into intaglio seals and used in ceremonial objects.

Spinel: A Versatile and Durable Gem

Spinel is a mineral composed of magnesium aluminum oxide and is found in a wide range of colors, including red, pink, blue, and black. The most popular shades associated with August are pink and red, which closely resemble ruby. Spinel is formed in metamorphic and igneous rocks, often in association with corundum (the mineral that includes ruby and sapphire).

The most significant sources of spinel include Afghanistan, Sri Lanka, Myanmar, and Tanzania. These regions have produced some of the finest and most historically significant spinel specimens. Spinel is known for its brilliance and clarity, making it a desirable gem for both classic and modern jewelry designs.

Gemological Properties

Peridot: The Green Fire

Peridot is known for its vibrant green color, which is caused by the presence of iron in its chemical composition. It has a hexagonal crystal system and is typically found in well-formed crystals. Peridot is relatively soft, with a Mohs hardness of 6.5 to 7, which means it is not as durable as harder gemstones like diamond or sapphire. It is also cleavable, meaning it can be split along specific planes, so care must be taken to avoid chipping.

Sardonyx: The Banded Beauty

Sardonyx is a banded agate and a variety of chalcedony. Its distinctive banding is one of its most notable features, and it is often carved into intaglios, cameos, and jewelry pieces. Sardonyx is relatively durable, with a Mohs hardness of 6.5 to 7, and it does not have cleavage, making it more resistant to chipping than peridot. It is also easily carved, making it a popular choice for carved gemstone jewelry.

Spinel: The Ruby Look-Alike

Spinel is a hard and durable gemstone, with a Mohs hardness of 8, making it very suitable for everyday wear in jewelry. It is isotropic, meaning it does not have birefringence, and it is not cleavable, so it is less prone to damage than peridot. Spinel is known for its brilliance and clarity, and its deep red and pink varieties are particularly popular for ring settings and necklaces.

Symbolism and Metaphysical Beliefs

Peridot – The Stone of Positivity

Peridot has long been associated with positive energy, prosperity, and protection. In ancient Egypt, it was believed to ward off nightmares and evil spirits, and it was often used in protective amulets. The stone was also thought to enhance clarity of thought and emotional balance, making it a popular choice for those seeking mental and emotional well-being.

In modern times, peridot is still considered a stone of positivity and renewal. It is often used in spiritual practices to promote joy, abundance, and healing. Peridot is also said to be a stone of the sun, bringing light and energy into one's life.

Sardonyx – The Stone of Courage and Willpower

Sardonyx has been used for centuries as a stone of courage and willpower. In ancient times, it was believed to help warriors in battle and was often carved into seals and talismans. It was also associated with stability, self-control, and protection, making it a valuable gemstone for those seeking strength and confidence.

In modern metaphysical practices, sardonyx is used to enhance focus, discipline, and determination. It is also believed to promote good fortune and success, particularly in business and personal endeavors.

Spinel – The Stone of Passion and Clarity

Spinel is a stone of passion, energy, and emotional clarity. Its vibrant red and pink colors make it a symbol of love, vitality, and emotional strength. In ancient times, spinel was used in royal jewelry and was believed to bring good fortune and protection.

In modern metaphysical beliefs, spinel is used to enhance emotional balance, self-expression, and creativity. It is also believed to help clear emotional blockages and promote inner strength and resilience.

Care and Cleaning

Peridot: Gentle Handling for a Delicate Gem

Peridot is a relatively soft gemstone with a Mohs hardness of 6.5 to 7, and it is cleavable, meaning it can be split along specific planes. This makes it susceptible to chipping or breaking if it is struck in the wrong direction. Therefore, it is important to handle peridot jewelry with care.

To clean peridot, use a soft cloth and warm, soapy water. Avoid using ultrasonic cleaners, as they can cause damage to the stone. It is also best to avoid harsh chemicals and abrasives, which can scratch or dull the surface of the gemstone.

When storing peridot, keep it separate from harder gemstones to prevent scratches. It is also a good idea to remove peridot jewelry before engaging in physical activities or sports, as the stone can be easily damaged.

Sardonyx: Durable and Easy to Care For

Sardonyx is a more durable gemstone than peridot, with a Mohs hardness of 6.5 to 7, and it does not have cleavage, making it less prone to chipping. It is also easily cleaned and can be polished to a high luster.

To clean sardonyx, use a soft cloth and warm, soapy water. You can also use a mild detergent and a soft brush to remove dirt and debris. Sardonyx is not sensitive to ultrasonic cleaners, so this is an acceptable option for thorough cleaning.

When storing sardonyx, it is safe to keep it with other gemstones, as it is not easily scratched. It is also not sensitive to light, so it can be displayed or worn in bright environments without fading or damage.

Spinel: A Hard and Durable Gem

Spinel is a very durable gemstone, with a Mohs hardness of 8, making it ideal for everyday wear in jewelry. It is not cleavable and is not sensitive to light or heat, making it a low-maintenance gemstone.

To clean spinel, use a soft cloth and warm, soapy water. You can also use an ultrasonic cleaner, as spinel is not sensitive to this method of cleaning. Spinel is resistant to chemicals and abrasives, so it can be cleaned with a variety of methods without risk of damage.

When storing spinel, it is safe to keep it with other gemstones, as it is not easily scratched. It is also not sensitive to light, so it can be displayed or worn in bright environments without fading or damage.

Conclusion

The August birthstones—peridot, sardonyx, and spinel—represent a rich and diverse array of gemological properties, historical significance, and cultural symbolism. Each stone has its own unique geological origin, color, and meaning, making them valuable choices for jewelry and gemstone enthusiasts.

Peridot, with its vibrant green color, is the most well-known of the August birthstones and has a long and storied history in ancient Egypt and beyond. Sardonyx, the oldest of the August birthstones, is a banded agate with a distinctive striped appearance and has been used in jewelry, amulets, and seals for thousands of years. Spinel, the newest addition to the August birthstone list, has been rediscovered and appreciated in recent years for its brilliance, durability, and beauty.

Whether you are a gemstone enthusiast, a jewelry buyer, or a student of gemology, the August birthstones offer a fascinating and rewarding subject of study. Their rich history, diverse properties, and cultural significance make them valuable and meaningful gems for those born in August and for those who appreciate the beauty and symbolism of gemstones.

Sources

1. Shop RMC: August Birthstone – Peridot & Spinel
2. GIA: August Birthstones
3. EC Design Studios: August Birthstone – Peridot
4. Luojewelry: August Birthstones
5. Plante Jewelers: How to Choose from the Three Beautiful August Birthstones
6. Jack Weir & Sons: All About August Birthstones – Peridot, Spinel, and Onyx
7. Sylvie Jewelry: August Birthstones