The gemstone tradition has long fascinated humanity, weaving together history, culture, and the natural world into a tapestry of meaning and symbolism. For those born in August, the tradition is especially intriguing, as this month is associated with three distinct gemstones: peridot, sardonyx, and spinel. Each of these stones carries its own unique history, gemological properties, and cultural significance. Together, they offer a rich and diverse representation of the August birthstone tradition, blending ancient roots with modern recognition.
This article delves into the origins and evolution of these gemstones as birthstones, explores their geological and physical properties, and discusses the meanings and beliefs associated with them. It also considers practical aspects such as care and use in jewelry. By the end, readers will gain a deeper appreciation for the August birthstones and the reasons behind their enduring popularity.
History and Lore
The tradition of birthstones is believed to have originated in ancient times, with one of its earliest references found in the Old Testament of the Bible, where the high priest’s breastplate was adorned with twelve gemstones, each representing one of the Twelve Tribes of Israel. This early association of gemstones with specific times of the year laid the foundation for later traditions.
By the 15th century, European cultures had developed their own versions of the birthstone calendar. These ancient or traditional birthstones were often based on local customs and the availability of certain stones. As time passed, the tradition evolved further, and by the 20th century, a more standardized list emerged, particularly in North America and Europe, where slight variations in the birthstone assignments became common.
In the case of August, the original or "ancient" birthstone was onyx. This gemstone, known for its striking contrast between light and dark bands, was widely used in cameos and carvings, and its hardness and durability made it a popular choice for jewelry. Over time, peridot became the primary or "traditional" birthstone for August, and in 2016, the American Gem Trade Association (AGTA) officially added spinel as the modern August birthstone, marking a new chapter in the August birthstone tradition.
Each of these stones carries a unique historical journey. Peridot, for instance, was revered by the ancient Egyptians, who referred to it as the "Gem of the Sun" and believed it could ward off nightmares and evil spirits. Sardonyx, on the other hand, was highly valued in ancient Rome, where it was used in cameos and signet rings, and its durability and versatility made it a favorite among jewelers. Spinel, though relatively new to the birthstone list, has a long and glamorous history, having been mistaken for ruby in royal collections and even used in crown jewels.
Geological Formation and Sources
Peridot
Peridot is a gem-quality variety of the mineral olivine, and its green color is due to the presence of iron. It forms deep within the Earth's mantle, often brought to the surface through volcanic activity. This process can also result in peridot being found in meteorites, making it one of the few extraterrestrial gemstones. In fact, peridot has been identified in space rocks that have fallen to Earth, including the Allende meteorite and pallasite meteorites, which are rich in olivine.
Geologically, peridot is most commonly found in mafic and ultramafic rocks, such as basalt and peridotite, and is often associated with volcanic regions. The best-quality peridot has traditionally been mined in Egypt, where it was first discovered around 2000 BCE. Other notable sources include Burma (Myanmar), the United States (Hawaii, Arizona), Brazil, Mexico, Pakistan, and China. The iron content in peridot determines its hue, ranging from yellowish green to deep olive or even brownish green.
Sardonyx
Sardonyx is a type of onyx, which is a banded form of chalcedony, a microcrystalline quartz. It is characterized by its distinct banding, usually reddish or brownish bands over a white or pale background. This gemstone is formed in sedimentary and volcanic rock deposits, where silica-rich water seeps through cracks and cavities, depositing layered chalcedony over time.
Historically, sardonyx was widely mined in the ancient world, with Sardinia being one of the most important sources. The Roman Empire relied heavily on sardonyx for cameos and signet rings, and its durability made it a popular choice for engraved jewelry. Other notable sources of sardonyx include India, Brazil, and the United States, where it is still mined today for both industrial and ornamental use.
Spinel
Spinel is a mineral composed of magnesium aluminum silicate and is often confused with ruby and sapphire due to its similar appearance and refractive properties. It can occur in a wide range of colors, including red, pink, orange, yellow, green, blue, and black, making it one of the most versatile gemstones. Its hardness (8 on the Mohs scale) and brilliant luster make it ideal for jewelry, and it has been mistaken for ruby in many royal collections.
Historically, spinel was mined in regions such as Burma (Myanmar), Afghanistan, and Sri Lanka, and its rich red varieties were particularly prized. Some of the most famous spinels include the "Black Prince's Ruby", which is actually a red spinel, and the "Timur Ruby", another notable spinel with a deep red color. These stones were mistaken for rubies for centuries and were used in royal crowns and regalia.
In 2016, the American Gem Trade Association (AGTA) officially recognized spinel as the modern August birthstone, acknowledging its beauty, rarity, and historical significance. This decision reflects a growing appreciation for alternative gemstones and the desire to expand the birthstone tradition to include new and underappreciated stones.
Gemological Properties
Peridot
Peridot is a silicate mineral and a member of the olivine group. Its chemical formula is (Mg, Fe)₂SiO₄, with the iron content being the primary determinant of its color. The refractive index of peridot ranges from 1.65 to 1.69, and it has a birefringence of 0.035 to 0.038, which can cause double refraction in some pieces. Peridot has a specific gravity of 3.34, and its hardness on the Mohs scale is 6.5 to 7, making it relatively durable, though not as hard as diamond or corundum.
Peridot is known for its vibrant green color, which can vary from yellowish green to deep olive or even brownish green, depending on the iron content. It is transparent to translucent, with inclusions that are often visible to the naked eye. These inclusions, which can include small crystals or gas bubbles, are characteristic of natural peridot and are considered part of its charm.
Sardonyx
Sardonyx is a banded form of chalcedony, a microcrystalline quartz, and is composed of silica (SiO₂). It is translucent to opaque, with distinct banding patterns that give it a striking visual contrast. The bands are usually reddish or brownish over a white or pale background, and the hardness of sardonyx on the Mohs scale is 6.5 to 7, making it durable enough for everyday wear.
Sardonyx is typically cut into cabochons, cameos, and signet rings, and its ability to take a high polish makes it a popular choice for engraved jewelry. It is often carved with intricate designs, and its durability allows for detailed carvings that can be preserved for centuries.
Spinel
Spinel is a mineral composed of magnesium aluminum silicate, with the chemical formula MgAl₂O₄. It is available in a wide range of colors, including red, pink, orange, yellow, green, blue, and black, and its hardness on the Mohs scale is 8, making it one of the hardest gemstones. Spinel has a refractive index of 1.718 to 1.736, and its specific gravity ranges from 3.6 to 4.0, depending on the color and composition.
Spinel is known for its brilliance and fire, and its high refractive index gives it a sparkling appearance that is similar to ruby and sapphire. It is often cut into round, oval, or cushion shapes, and its clarity is usually excellent, with few inclusions. Spinel is also available in synthetic forms, which are indistinguishable from natural stones to the naked eye.
Symbolism and Metaphysical Beliefs
Peridot
Peridot has been associated with a wide range of meanings and beliefs throughout history. The ancient Egyptians believed it could ward off nightmares and evil spirits, and they referred to it as the "Gem of the Sun" and the "Evening Emerald". In medieval Europe, peridot was considered a stone of protection, and it was used in amulets and talismans to ward off negative energy and promote peace and tranquility.
In modern metaphysical beliefs, peridot is thought to promote emotional balance, happiness, and contentment. It is believed to enhance positive energy, reduce stress, and encourage emotional stability. Peridot is also associated with prosperity and good fortune, making it a popular choice for those seeking success and abundance.
Sardonyx
Sardonyx has been used for thousands of years in protective and ceremonial jewelry, and it is associated with strength, courage, and protection. In ancient Rome, sardonyx was used in signet rings and cameos, and it was believed to provide protection and good fortune to the wearer.
In modern metaphysical beliefs, sardonyx is thought to enhance willpower, promote self-discipline, and provide protection against negative influences. It is also associated with grounding and stability, and it is often used in jewelry to help the wearer stay centered and focused.
Spinel
Spinel has a rich history of symbolic and metaphysical associations, particularly in royal and noble circles. In ancient times, spinel was believed to have protective and healing properties, and it was used in amulets and talismans to ward off evil and bring good fortune.
In modern metaphysical beliefs, spinel is thought to enhance emotional balance, promote love and compassion, and encourage self-expression. Red spinel is particularly associated with passion, vitality, and courage, and it is often used in jewelry to promote confidence and assertiveness.
Care and Cleaning
Peridot
Peridot is a relatively durable gemstone, but it is not as hard as diamond or corundum, and it can be damaged by hard knocks or abrasion. It is also sensitive to heat, and it should not be exposed to high temperatures, as this can cause fractures or discoloration.
To clean peridot jewelry, it is best to use a mild soap and warm water, and a soft brush or cloth can be used to remove dirt and debris. Ultrasonic cleaners and steam cleaners should be avoided, as they can cause damage to the gemstone or its setting.
When storing peridot jewelry, it should be kept in a soft pouch or lined box to prevent scratches and abrasion. It should also be stored separately from harder gemstones, such as diamonds or sapphires, to avoid damage.
Sardonyx
Sardonyx is a durable gemstone, and it can be cleaned with a mild soap and warm water. A soft brush or cloth can be used to remove dirt and debris, and it is safe to use ultrasonic and steam cleaners on sardonyx, as long as it is free of inclusions or fractures.
When storing sardonyx jewelry, it should be kept in a dry, cool place to prevent any damage from moisture or heat. It should also be stored separately from harder gemstones, such as diamonds or sapphires, to avoid scratches or abrasion.
Spinel
Spinel is a hard and durable gemstone, and it can be cleaned with a mild soap and warm water. A soft brush or cloth can be used to remove dirt and debris, and it is safe to use ultrasonic and steam cleaners on spinel, as long as it is free of inclusions or fractures.
When storing spinel jewelry, it should be kept in a soft pouch or lined box to prevent scratches and abrasion. It should also be stored separately from harder gemstones, such as diamonds or sapphires, to avoid damage.
Conclusion
The August birthstones—peridot, sardonyx, and spinel—each offer a unique blend of history, beauty, and symbolism. From the ancient Egyptian reverence for peridot as the "Gem of the Sun", to the Roman appreciation for sardonyx in cameos and signet rings, and the modern recognition of spinel as a new and vibrant addition to the birthstone tradition, these stones reflect a rich and evolving heritage.
Each of these gemstones has its own distinct gemological properties, making them suitable for different types of jewelry and wearing conditions. Whether you are drawn to the vibrant green of peridot, the bold banding of sardonyx, or the brilliant colors of spinel, there is an August birthstone to suit every preference and style.
As with any gemstone, it is important to understand its properties and care requirements to ensure its longevity and beauty. With the right care and handling, August birthstone jewelry can be treasured for generations, carrying with it the rich history and symbolism of these remarkable stones.