August, a month often associated with the vibrant energy of late summer, is uniquely distinguished in the world of birthstones by offering not one, but three official gemstones: Peridot, Spinel, and Sardonyx. These gemstones each carry a distinct charm, historical depth, and symbolic meaning, making August a particularly rich and fascinating month in the birthstone calendar. This article delves into the geological origins, cultural significance, and gemological properties of these three stones, offering a comprehensive overview for gemstone enthusiasts, jewelry buyers, and students of gemology.
Introduction
For those born in August, the birthstone options are not limited to a single gemstone. Instead, the month is uniquely blessed with three: Peridot, Spinel, and Sardonyx. Each of these stones has its own distinct history, appearance, and symbolism. Peridot, the most widely recognized of the three, is a vibrant yellow-green gemstone that has been cherished for centuries. Spinel, once mistaken for ruby and now enjoying a resurgence in popularity, offers a dazzling array of colors. Sardonyx, the earliest of the three, has biblical roots and was one of the original foundation stones of the high priest's breastplate.
This article explores the unique qualities of each August birthstone. We begin with an overview of the historical and cultural significance of these gemstones, followed by an in-depth look at their geological formation and sources. We then examine their gemological properties, including hardness, clarity, and color, and discuss their symbolic and metaphysical meanings. Finally, we provide practical advice on caring for and cleaning each of these stones.
History and Lore
Sardonyx: The Ancient August Birthstone
Sardonyx is the oldest of the three August birthstones, with a history that dates back over 4,000 years. It is one of the most ancient gemstones in recorded history and was even mentioned in the Bible. In the Book of Exodus, it was one of the 12 stones on the high priest's breastplate, representing one of the 12 tribes of Israel. This connection to ancient religious traditions underscores the stone's historical importance and enduring symbolism.
Sardonyx is a type of chalcedony, composed of alternating layers of sard (a reddish-brown chalcedony) and onyx (a black or white chalcedony). Its distinctive banded pattern resembles a zebra's stripes, giving it a unique and recognizable appearance. This gemstone was not only used for religious and ceremonial purposes but also for amulets and protective charms in various ancient civilizations, including Egypt and Rome.
Peridot: The Golden Green of the Earth’s Mantle
Peridot is the most vibrant and widely recognized of the three August birthstones. Known for its yellow-green to greenish-yellow hue, it has been cherished for millennia. The name "peridot" is believed to derive from the Arabic word "faridat", meaning "gem", and it has been found in numerous archaeological sites across the globe.
Peridot is unique in that it forms deep within the Earth's mantle, making it one of the few gemstones that originate from such extreme depths—alongside diamonds. It is often found in hardened lava flows, brought to the surface by volcanic activity, or in meteorites that have traveled from outer space. This cosmic origin adds to its allure and makes it one of the few gemstones with an extraterrestrial connection.
Historically, peridot was often mistaken for other gems like topaz and emerald. A famous example is the Shrine of the Three Holy Kings in Cologne Cathedral, which was believed to be decorated with emeralds but was actually adorned with peridot. Some historians even speculate that Cleopatra’s famed emerald collection may have consisted of peridots.
Spinel: The Revival of a Misunderstood Gem
Spinel is a relatively newer addition to the August birthstone list, having been officially added in 2016 by the American Gem Trade Association (AGTA) and Jewelers of America. Prior to this, spinel was often mistaken for other gems, particularly ruby, and was underappreciated for much of its history.
The name "spinel" comes from the Latin word "spina", meaning "thorn", referring to the gem's crystalline form. Spinel can occur in a wide range of colors, including red, pink, orange, and even colorless, but the red and pink varieties are the most commonly associated with August. Its recent rise in popularity can be attributed to its vibrant colors, durability, and affordability, making it an excellent alternative to more expensive stones like ruby.
Spinel's inclusion as an August birthstone in 2016 reflects a broader trend in the gemstone industry toward recognizing and celebrating lesser-known stones with unique qualities and histories.
Geological Formation and Sources
Sardonyx
Sardonyx is a type of chalcedony, a microcrystalline form of silica (SiO₂). It is composed of alternating bands of sard, a reddish-brown chalcedony, and onyx, a white or black chalcedony. This banding is what gives sardonyx its distinctive striped appearance.
Sardonyx is typically found in volcanic rocks, where it forms in the cavities and fissures of these rocks through the slow deposition of silica-rich fluids. It is most commonly mined in India, Brazil, and Nepal, where it is extracted from sedimentary and metamorphic rock formations. Sardonyx is relatively abundant and affordable, making it a popular choice for jewelry and decorative objects.
Peridot
Peridot is a gemstone variety of the mineral olivine, a silicate mineral with the chemical formula (Mg,Fe)₂SiO₄. It forms under extreme high-pressure and high-temperature conditions deep within the Earth’s mantle, at depths of 80 to 200 kilometers. These conditions cause the magnesium and iron within the mineral to create the yellow-green to greenish-yellow color that is characteristic of peridot.
Peridot is brought to the surface through volcanic eruptions, where it is carried up by magma, or it is found in meteorites, particularly in pallasite meteorites—a type of stony meteorite that contains nickel-iron and peridot inclusions.
The largest and most famous deposits of peridot are found on the Red Sea island of Zabargad, also known as St. John’s Island. Other notable sources include Arizona and New Mexico in the United States, as well as Madagascar and Myanmar. Peridot is also found in volcanic glass and basaltic rocks.
Spinel
Spinel is a garnet group mineral with the general chemical formula MgAl₂O₄, though it can also contain iron, chromium, or manganese, which influence its color. It forms in igneous rocks, particularly in mafic and ultramafic rocks, where it crystallizes under high-temperature and high-pressure conditions.
Spinel is found in a variety of geological environments, including metamorphic rocks, lava flows, and placer deposits. The most famous historical sources of spinel include Afghanistan, Burma (Myanmar), and Sri Lanka, though modern production is also significant in Vietnam, Madagascar, and Tanzania.
Spinel is known for its vibrant colors, with red, pink, and orange being the most sought-after varieties. Its hardness (8 on the Mohs scale) and luster make it an excellent gemstone for everyday wear, and its affordability compared to similar-colored stones like ruby has contributed to its growing popularity.
Gemological Properties
Sardonyx
- Chemical Composition: Silica (SiO₂), with alternating bands of sard and onyx
- Hardness: 6.5–7 on the Mohs scale
- Color: Reddish-brown and white or black bands
- Clarity: Typically opaque, with visible banding
- Cut: Typically cabochon or domed shapes to emphasize banding
- Luster: Waxy to vitreous
- Origin: India, Brazil, Nepal
Sardonyx is relatively durable for its hardness, but because it is opaque and banded, it is not as commonly faceted as other gemstones. It is often used in intaglios, cameos, and pendants, where the banding can be showcased in a visually appealing way.
Peridot
- Chemical Composition: (Mg,Fe)₂SiO₄
- Hardness: 6.5–7 on the Mohs scale
- Color: Yellow-green to greenish-yellow
- Clarity: Often inclusion-free or with small inclusions
- Cut: Can be cut into a wide variety of shapes, including round, oval, emerald, and princess
- Luster: Vitreous
- Origin: Zabargad Island, Arizona, Madagascar, Myanmar
Peridot is known for its vibrant color and clarity, and high-quality peridots are often free of inclusions. It is relatively soft compared to other gemstones, so it is best suited for protective settings to prevent chipping or abrasion.
Spinel
- Chemical Composition: MgAl₂O₄ (with possible substitutions of iron, chromium, or manganese)
- Hardness: 8 on the Mohs scale
- Color: Red, pink, orange, and even colorless
- Clarity: Often very clean, with high transparency
- Cut: Can be cut into a wide variety of shapes, including round, oval, and princess
- Luster: Vitreous
- Origin: Afghanistan, Myanmar, Sri Lanka, Vietnam, Madagascar, Tanzania
Spinel is prized for its brilliance, clarity, and durability. It is one of the few gemstones that can rival ruby in color and brilliance, and its 8 on the Mohs scale makes it suitable for daily wear. The red and pink varieties are particularly popular as August birthstones.
Symbolism and Metaphysical Beliefs
Sardonyx
Sardonyx has long been associated with protection, courage, and strength. In ancient times, it was worn as an amulet to ward off evil spirits and to provide protection in battle. It was also believed to bring good fortune and success, particularly in endeavors that required perseverance and determination.
In medieval Europe, sardonyx was used as a protective stone for travelers and warriors. It was also believed to promote emotional balance and stability, helping the wearer to remain calm and composed in times of stress or conflict.
In modern metaphysical traditions, sardonyx is still considered a stone of protection and courage, particularly for those in leadership roles or those facing challenging situations. It is also believed to help with self-confidence and willpower, making it a valuable stone for those seeking to overcome obstacles.
Peridot
Peridot is one of the most positive and uplifting gemstones in the birthstone calendar. It is associated with growth, prosperity, love, and loyalty. In ancient times, it was believed to bring good fortune and happiness, and it was often used in protective charms and healing amulets.
Peridot is also believed to have calming and soothing properties, helping to reduce anxiety, stress, and negative emotions. It is particularly valued for its ability to clear the mind and promote mental clarity, making it a popular stone for meditation and spiritual practices.
In modern metaphysical traditions, peridot is often used to boost self-esteem, encourage personal growth, and promote inner peace. It is also associated with healing and renewal, making it a valuable stone for those seeking to overcome emotional or physical challenges.
Spinel
Spinel is a stone of passion, courage, and vitality. It is often associated with love, romance, and emotional healing, and it is believed to help the wearer open their heart and express their emotions more freely.
In ancient times, spinel was believed to bring good luck and protection, particularly in times of danger or conflict. It was also used as a stone of wisdom and intuition, helping the wearer to make better decisions and navigate difficult situations.
In modern metaphysical traditions, spinel is considered a stone of transformation and empowerment. It is believed to help the wearer overcome obstacles, build confidence, and take action in their life. It is also associated with creativity and inspiration, making it a valuable stone for artists, writers, and other creative individuals.
Care and Cleaning
Sardonyx
Sardonyx is relatively durable, with a hardness of 6.5–7 on the Mohs scale, but because it is opaque and banded, it is best to avoid abrasive or harsh cleaning methods. It can be cleaned with warm, soapy water and a soft cloth. Avoid ultrasonic cleaners, as the vibrations may damage the banding or the setting.
When storing sardonyx jewelry, it is best to keep it in a soft pouch or cloth-lined box to prevent scratches from harder gemstones. It is also advisable to remove sardonyx jewelry before engaging in physical activities or wearing it in high-temperature environments, as extreme heat may cause the bands to fade or the stone to crack.
Peridot
Peridot is relatively soft compared to other gemstones, with a hardness of 6.5–7 on the Mohs scale, so it is prone to scratches and abrasions. It is also sensitive to heat, so it is best to avoid exposing it to high temperatures, such as those from a jeweler's torch or a hot sauna.
To clean peridot, it is best to use warm, soapy water and a soft brush or cloth. Avoid ultrasonic cleaners, as the vibrations may damage the inclusions or the setting. When storing peridot jewelry, it is best to keep it in a soft pouch or cloth-lined box, and to remove it before engaging in physical activities or wearing it in high-temperature environments.
Spinel
Spinel is a hard and durable gemstone, with a hardness of 8 on the Mohs scale, making it suitable for daily wear and long-term use. It is also resistant to heat and chemicals, making it a low-maintenance gemstone.
To clean spinel, you can use warm, soapy water and a soft brush or cloth. Ultrasonic cleaners are also safe for spinel, as long as the stone is not set in a delicate or fragile setting. When storing spinel jewelry, it is best to keep it in a soft pouch or cloth-lined box to prevent scratches from harder gemstones.
Conclusion
The August birthstones—Peridot, Spinel, and Sardonyx—offer a unique and fascinating combination of color, history, and symbolism. Each of these gemstones has its own distinct qualities and characteristics, making them valuable and meaningful choices for those born in August.
Peridot, with its vibrant yellow-green color, is a symbol of growth, prosperity, and protection. Sardonyx, the oldest of the three, carries a rich historical and religious significance, particularly in ancient biblical and Roman traditions. Spinel, the newest addition to the August birthstone list, is a durable, colorful, and affordable gemstone that is gaining popularity in modern jewelry.
Whether you are selecting a birthstone for a loved one, designing a piece of jewelry, or simply exploring the world of gemstones, the August birthstones offer a rich tapestry of color, history, and meaning that is both beautiful and enduring.