August 31 marks the end of a month rich in gemological tradition, and for those born on this day, it is associated with three distinct birthstones: peridot, spinel, and sardonyx. Each of these gems carries a unique set of properties, histories, and meanings, reflecting the diverse cultural and geological landscapes from which they originate. This article provides an in-depth exploration of these three August 31 birthstones, covering their origins, physical and metaphysical attributes, and their roles in jewelry and human history.
Introduction
The birthstone tradition, which assigns specific gemstones to each month of the year, has roots in ancient civilizations and continues to influence jewelry design, personal symbolism, and even gemological study today. For August 31, the primary birthstone is peridot, a gemstone with a rich history dating back thousands of years. However, the inclusion of spinel and sardonyx in the August 31 birthstone list adds depth and variety to the celebration of this date. These stones each have unique geological and cultural narratives, making them fascinating subjects for gemstone enthusiasts and historians alike.
This article will explore the properties, history, and significance of peridot, spinel, and sardonyx, drawing from authoritative sources to ensure scientific and historical accuracy. It will also consider the practical aspects of caring for these stones in jewelry, and the cultural and metaphysical beliefs that have surrounded them across different eras and regions.
History and Lore
Peridot: The Gem of the Sun
Peridot has a long and storied history, with some of the earliest references to the gemstone dating back over 3,000 years. The ancient Egyptians were among the first to recognize its value, referring to it as the “gem of the sun” due to its vibrant green color and the way it seemed to glow with an inner light. It was believed that the gemstone was a gift from the sun god, and it was often used in jewelry and amulets to protect its wearer from illness and misfortune.
Historical records indicate that peridot was mined on the volcanic island of Zabargad, located in the Red Sea. The island, known as St. John’s Island in modern times, was a primary source of peridot for the ancient Egyptians and other civilizations. The gemstone was so highly prized that it was often buried with the dead to ensure their safe passage to the afterlife.
Peridot also holds a special place in Hawaiian culture, where it is known as "Pele's tears." According to legend, the goddess Pele, who is said to control the flow of lava, cried when her heart was broken. Her tears, when they fell into the lava, formed peridot. This myth has contributed to the gemstone’s association with emotional healing and renewal.
Spinels: The Great Imposters
Spinels have a more recent but equally intriguing history. Known for centuries as “Balas ruby” or “rubicelle,” red spinels were often mistaken for rubies due to their similar appearance. This confusion persisted until the late 18th century, when French mineralogist Jean-Baptiste Louis Romé de l’Isle proved that spinel and ruby are distinct minerals.
One of the most famous examples of a spinel mistaken for a ruby is the Black Prince’s Ruby, which is set in the Imperial State Crown of the United Kingdom. Despite its name, the gem is actually a large spinel. This misidentification highlights the challenges of gemstone identification in the pre-scientific era and underscores the importance of modern gemological techniques in distinguishing between similar-looking stones.
Spinels have also played a role in various cultures throughout history. In India and Central Asia, spinels were highly valued for their vibrant colors and were often used in royal jewelry and ceremonial objects. Their discovery in Burma (now Myanmar) and other regions contributed to their widespread use in both Western and Eastern jewelry traditions.
Sardonyx: The Original August Birthstone
Sardonyx is a red and white banded variety of onyx, a form of chalcedony quartz. It has been recognized as a gemstone for over 4,000 years and was once considered the original August birthstone. The name “sardonyx” is derived from the Greek words “sardis,” meaning “red,” and “onyx,” referring to the banded structure of the stone.
Sardonyx was widely used by the ancient Egyptians, Greeks, and Romans, who believed it to be a powerful protective stone. It was often carved into seals and amulets and was thought to ward off evil spirits and bring good fortune. In Christian theology, sardonyx was associated with the strength of spiritual life and was believed to promote love and friendship.
During the Renaissance, sardonyx became a popular gemstone for signet rings and was used in both religious and secular jewelry. It was also associated with legal protection and was believed to assist the wearer in winning legal cases. In Sweden, naturalist and mystic Emanuel Swedenborg described sardonyx as representing “love of good and light,” further cementing its spiritual significance.
Geological Formation and Sources
Peridot
Peridot is a variety of the mineral olivine, which is composed of magnesium iron silicate. The gemstone forms deep within the Earth's mantle and is brought to the surface through volcanic activity. It can also be found in meteorites that have fallen to Earth, making it one of the few gemstones that originate from outer space.
The most significant sources of gem-quality peridot include the volcanic islands of Zabargad (St. John’s Island) in the Red Sea, as well as inclusions within lava flows in Hawaii. Peridot has also been found in other parts of the world, including Pakistan, China, and the United States. The color of peridot ranges from yellowish green to greenish yellow, with the most valuable stones exhibiting a rich, vibrant green hue.
Spinel
Spinel is a mineral composed of magnesium aluminum oxide, with the chemical formula MgAl₂O₄. It is found in a wide range of colors, including red, blue, pink, orange, and black. The red variety of spinel, known as rubicell, is particularly valuable and is often confused with ruby.
Spinel forms in igneous rocks and is commonly found in metamorphic environments. The most notable sources of gem-quality spinel include Burma (Myanmar), Afghanistan, and Sri Lanka. In recent years, spinel deposits have also been discovered in Vietnam and Madagascar. The gemstone is known for its clarity and brilliance, and high-quality spinel can rival the beauty of ruby and sapphire.
Sardonyx
Sardonyx is a type of onyx that is composed of microcrystalline quartz. It forms in sedimentary and volcanic rocks and is often found in banded layers. The red coloration in sardonyx is due to the presence of iron, while the white bands are caused by the absence of iron and the presence of other minerals.
Historically, sardonyx was mined in the region of Sardinia, from which it gets its name. Today, significant sources of sardonyx include India, Brazil, and the United States. The gemstone is known for its durability and is often used in engraved seals, signet rings, and other decorative items.
Gemological Properties
Peridot
Peridot is a relatively soft gemstone with a hardness of 6.5 to 7 on the Mohs scale. This makes it more susceptible to scratches and damage than harder gemstones like diamond or corundum (ruby and sapphire). Despite its lower hardness, peridot is known for its excellent transparency and brilliance.
The refractive index of peridot ranges from 1.65 to 1.69, and it exhibits a vitreous (glassy) luster. Peridot is typically found in a range of green colors, from yellow-green to deep green, depending on the amount of iron in the crystal structure. The most valuable and sought-after peridot is a deep, rich green with a high degree of clarity.
Peridot is also known for its pleochroism, meaning that it can display different colors when viewed from different angles. This property is particularly noticeable in larger stones and can add to the gem’s visual appeal.
Spinels
Spinels vary in hardness depending on their composition, but most gem-quality spinels have a hardness of 7.5 to 8 on the Mohs scale. This makes them more durable than peridot and suitable for use in a wide range of jewelry settings, including rings and bracelets.
The refractive index of spinel ranges from 1.718 to 1.762, and it has a vitreous to subadamantine luster. Spinels are known for their clarity and brilliance, with the best specimens displaying high transparency and excellent fire. Red spinels, in particular, are highly valued for their vibrant color and can rival the beauty of ruby.
Spinels are also known for their pleochroism, although this property is more pronounced in certain colors, such as blue and green. The most valuable spinels are those with a deep red or blue color, high clarity, and a well-cut facet structure.
Sardonyx
Sardonyx has a hardness of 6.5 to 7 on the Mohs scale, making it relatively durable for a chalcedony. It is known for its fine, even texture and its ability to take a high polish. The refractive index of sardonyx ranges from 1.48 to 1.53, and it has a waxy to vitreous luster.
Sardonyx is typically found in banded layers, with the red bands caused by the presence of iron and the white bands caused by the absence of iron. The most valuable sardonyx is characterized by clear, distinct bands and a high degree of translucency. Sardonyx is often used in engraved seals, signet rings, and other decorative items due to its durability and ability to hold fine detail.
Symbolism and Metaphysical Beliefs
Peridot
Peridot has long been associated with healing, protection, and emotional balance. In ancient Egyptian culture, it was believed to have the power to ward off illness and misfortune. It was also thought to bring good luck and was often worn as a protective amulet.
In more recent times, peridot has been associated with the heart chakra and is believed to promote feelings of compassion, love, and emotional healing. It is also thought to enhance one's ability to communicate and express emotions, making it a popular gemstone for those seeking emotional clarity.
Peridot is also believed to have a calming effect on the mind and is often used in meditation and spiritual practices. Some cultures believe that peridot can help to dispel negative thoughts and promote a sense of inner peace and tranquility.
Spinels
Spinels have a rich history of symbolic meaning, particularly in the case of red spinels. Historically, red spinels were believed to have the same protective and healing properties as rubies. They were often used in jewelry and amulets to ward off evil spirits and bring good fortune.
In modern metaphysical practices, red spinels are believed to enhance courage, confidence, and vitality. They are also thought to promote a sense of passion and energy, making them ideal for those seeking motivation and inspiration. Blue spinels, on the other hand, are associated with calmness, clarity, and spiritual insight.
Spinels are also believed to have a grounding effect on the mind and body, helping to stabilize emotions and promote a sense of balance. Some practitioners use spinels in meditation to enhance intuition and spiritual awareness.
Sardonyx
Sardonyx has a long history of symbolic meaning, particularly in ancient cultures. It was believed to be a powerful protective stone, capable of warding off evil spirits and bringing good fortune. In Roman culture, sardonyx was often used in signet rings and was believed to protect the wearer from illness and misfortune.
Sardonyx is also associated with love and friendship. It was believed to promote harmony in relationships and was often used in amulets to attract love and companionship. In Christian theology, sardonyx was associated with the strength of spiritual life and was believed to promote the love of friends and family.
In modern metaphysical practices, sardonyx is believed to promote self-control, discipline, and emotional stability. It is also thought to enhance one's ability to make sound decisions and to provide protection in legal and business matters. Sardonyx is often used in meditation to enhance clarity of thought and to promote a sense of inner strength and confidence.
Care and Cleaning
Peridot
Due to its relatively low hardness (6.5 to 7 on the Mohs scale), peridot requires careful handling to prevent scratches and damage. It is also sensitive to heat and sudden temperature changes, so it should be kept away from extreme temperatures.
To clean peridot jewelry, use a soft cloth and mild soap and warm water. A soft-bristled toothbrush can be used to gently scrub the stone, but it should be avoided if the stone has any inclusions or surface imperfections. After cleaning, the jewelry should be dried with a soft towel and stored in a cool, dry place.
Peridot should not be exposed to harsh chemicals or ultrasonic cleaners, as these can cause damage to the stone. It is also important to avoid exposing peridot to direct sunlight for prolonged periods, as this can cause the color to fade.
Spinels
Spinels are more durable than peridot, with a hardness of 7.5 to 8 on the Mohs scale, making them suitable for daily wear. However, they can still be damaged by harsh chemicals and sudden temperature changes.
To clean spinel jewelry, use a soft cloth and mild soap and warm water. A soft-bristled toothbrush can be used to gently scrub the stone, but it should be avoided if the stone has any inclusions or surface imperfections. After cleaning, the jewelry should be dried with a soft towel and stored in a cool, dry place.
Spinels should not be exposed to harsh chemicals or ultrasonic cleaners, as these can cause damage to the stone. It is also important to avoid exposing spinels to direct sunlight for prolonged periods, as this can cause the color to fade.
Sardonyx
Sardonyx is a relatively durable gemstone with a hardness of 6.5 to 7 on the Mohs scale, making it suitable for daily wear. However, it can still be damaged by harsh chemicals and sudden temperature changes.
To clean sardonyx jewelry, use a soft cloth and mild soap and warm water. A soft-bristled toothbrush can be used to gently scrub the stone, but it should be avoided if the stone has any inclusions or surface imperfections. After cleaning, the jewelry should be dried with a soft towel and stored in a cool, dry place.
Sardonyx should not be exposed to harsh chemicals or ultrasonic cleaners, as these can cause damage to the stone. It is also important to avoid exposing sardonyx to direct sunlight for prolonged periods, as this can cause the color to fade.
Conclusion
The birthstones associated with August 31—peridot, spinel, and sardonyx—each have a rich history, unique properties, and deep cultural significance. Peridot, with its vibrant green color and ancient Egyptian roots, has long been associated with the sun and renewal. Spinels, particularly the red variety, have a fascinating history of being mistaken for rubies and have only recently gained recognition as a distinct gemstone. Sardonyx, the original August birthstone, has been prized for thousands of years for its protective qualities and association with love and friendship.
Whether worn for their beauty, their historical significance, or their metaphysical properties, these gemstones continue to captivate and inspire. For those born on August 31, choosing one of these stones as a birthstone is not just a celebration of their birth date, but also a connection to the rich traditions and stories that have surrounded these gems for centuries.