The August birthstone is a unique trio of gemstones—peridot, spinel, and sardonyx—each with its own distinct geological origin, historical significance, and cultural symbolism. Unlike many months that feature a single birthstone, August stands out for its rich diversity, offering a range of colors, properties, and meanings. These gemstones have been treasured for millennia, from ancient civilizations to modern jewelry design. This article delves into the fascinating world of the August birthstones, exploring their formation, sources, gemological properties, cultural lore, and care instructions, all based on the most reliable and authoritative information available.
Introduction
The August birthstone ring is a meaningful and elegant choice for those born in the eighth month of the year. The ring often features one of three distinct gemstones—peridot, spinel, or sardonyx—each with a unique story and set of properties. Peridot, with its vibrant green hue, is a gem formed in extreme conditions, even found in meteorites. Spinel, once mistaken for ruby and sapphire, has gained increasing recognition for its beauty and versatility. Sardonyx, an ancient gemstone of layered chalcedony, has been used for carvings and seals for thousands of years.
This article will explore each of these gemstones in depth. We will examine their geological formation and sources, their historical and cultural significance, their gemological properties, and how best to care for these precious stones. By the end of this article, you will have a comprehensive understanding of the August birthstones and their enduring appeal.
History and Lore
Peridot: A Gem of Ancient Wonders
Peridot, the yellowish-green to greenish-yellow gem variety of the mineral olivine, has a history that stretches back to ancient times. Known as the "gem of the sun" in some cultures, peridot was widely used in jewelry and religious artifacts. One of the earliest known sources of peridot is the Egyptian island of Zabargad, historically known as Topazios, a name later associated with the gem topaz. The island was mined for peridot as early as 340–279 BCE, though some sources suggest even earlier use.
Peridot has often been confused with other green gems such as topaz and emerald. For example, the Shrine of the Three Holy Kings in Cologne Cathedral contains 200 carats of gems that were once thought to be emeralds, but are in fact peridot. Some historians even speculate that Cleopatra’s famed emerald collection may have actually been peridot.
The name "peridot" comes from the Arabic word "faridat", meaning "gem". In medieval Europe, peridot was used in chalices and churches and was believed to have protective powers. It was also worn as a talisman against evil spirits and the "terrors of the night". Peridot is also the gemstone that marks the 16th wedding anniversary, symbolizing enduring love and harmony.
Spinel: The Misunderstood Beauty
Spinel, the second of the August birthstones, has a long and intriguing history. For centuries, red spinel was mistaken for ruby, and pink spinel was often confused with ruby and sapphire. In fact, the "Black Prince’s Ruby" in the British Crown Jewels is actually a fine red spinel. This misidentification delayed the recognition of spinel as a gemstone in its own right.
Spinel was largely overlooked in the jewelry industry until the early 21st century, when collectors and jewelers began to appreciate its brilliance and color. In 2007, a discovery in Tanzania of pinkish and orangy red spinel captivated gem collectors. This marked a turning point in the gem's recognition and popularity. Today, spinel is valued for its durability and wide range of colors, from deep red to vivid orange and even rare blue and purple hues.
Spinel is believed to bring courage, confidence, and emotional clarity. It is also associated with love and passion, making it a popular gemstone for romantic jewelry.
Sardonyx: The Ancient Gem of Strength and Clarity
Sardonyx, the third August birthstone, is one of the oldest known gemstones. It is a type of chalcedony, a form of cryptocrystalline quartz, composed of alternating bands of sard (a reddish-brown to orange chalcedony) and onyx (a white or black chalcedony). Sardonyx has been used for carvings, especially cameos and intaglios, for millennia.
In ancient times, sardonyx was highly valued for its resistance to sticking to hot wax, making it ideal for Roman seals and signet rings. Roman soldiers even wore sardonyx rings with the image of Mars, the god of war, engraved on them for protection in battle.
Sardonyx is also believed to have been one of the stones in the High Priest’s breastplate as described in the Old Testament, symbolizing the strength of spiritual life. In modern times, sardonyx is associated with courage, happiness, and clear communication, and is thought to bring stability to relationships and partnerships.
Geological Formation and Sources
Peridot: From Earth's Mantle to Meteorites
Peridot is a unique gemstone in that it can be formed in two extraordinary ways: from volcanic lava and from meteorites. Most peridot is found in igneous rocks, particularly in ultramafic rocks such as peridotite, which are rich in magnesium and iron. These rocks are formed deep within the Earth’s mantle and are brought to the surface through volcanic activity.
Peridot is also found in pallasite meteorites, which are composed of nickel-iron and olivine. These meteorites are remnants of the cores of differentiated asteroids, and the peridot in them is of gem-quality, making it a truly cosmic gem.
Key sources of peridot include:
- Arizona (United States): The San Carlos Apache Reservation is one of the main sources of peridot in the U.S. The volcanic activity in the region thousands of years ago created the ideal conditions for peridot formation.
- Myanmar (formerly Burma): Known for its high-quality peridot, especially from the Kyaukpon mountainous region near Mogok, this source produces peridot with deep color and superb transparency.
- China, Pakistan, Vietnam, and Tanzania: These countries also produce peridot in varying colors and qualities.
- Hawaii: Peridot can be found in the sands of Peridot Beach, where the green-hued grains of sand shimmer in the sunlight.
Peridot can also be found in Egypt’s Zabargad Island, the oldest recorded source of the gem. Despite its beauty, the island has been known for its harsh conditions, earning it names like "Island of Death" and "Snake Island".
Spinel: A Diverse and Durable Gem
Spinel is a hard and durable gemstone with a Mohs hardness of 8, making it suitable for use in rings and other jewelry. Unlike peridot, spinel is not typically found in meteorites. Instead, it forms in igneous and metamorphic rocks, especially in mica schist and garnet-bearing rocks.
Key sources of spinel include:
- Tanzania: Known for its pink and orangy-red spinel, this country became a significant source after a major discovery in 2007.
- Myanmar (Burma): A traditional source of fine red and pink spinel, often mistaken for ruby in the past.
- Sri Lanka: Known for producing a wide range of spinel colors, including blue and violet.
- Afghanistan and Vietnam: These countries also produce notable spinel deposits.
Spinel is also known to be stable under light and chemicals, but high heat can cause some colors to fade, especially in lighter tones.
Sardonyx: Layers of History and Beauty
Sardonyx is a type of chalcedony, a form of cryptocrystalline quartz, and is composed of alternating layers of sard and onyx. These layers give sardonyx its distinctive banded appearance, making it ideal for cameos and intaglios.
Key sources of sardonyx include:
- India: Known for producing sardonyx with good contrast between the different colored layers.
- Brazil, Germany, Czechoslovakia, Madagascar, Uruguay, and the United States: These countries also have notable sardonyx deposits.
Sardonyx is often dye-treated to enhance or alter its colors, especially in commercial jewelry. As with other chalcedony, high heat can affect the color of dyed sardonyx, so care must be taken during jewelry manufacturing and repairs.
Gemological Properties
Peridot
| Property | Value |
|---|---|
| Chemical Formula | (Mg,Fe)₂SiO₄ |
| Color | Yellowish green to greenish yellow |
| Hardness (Mohs) | 6.5–7 |
| Refractive Index | 1.65–1.70 |
| Specific Gravity | 3.32–3.48 |
| Luster | Vitreous |
| Cleavage | Perfect in one direction |
| Fracture | Conchoidal |
| Transparency | Transparent to translucent |
| Inclusions | Common, including iron-rich specks and fractures |
Peridot has a relatively low hardness compared to other gemstones, which means it is softer than many gems and can be easily scratched or damaged. It is also susceptible to acids and acidic perspiration, which can degrade its appearance over time.
Spinel
| Property | Value |
|---|---|
| Chemical Formula | MgAl₂O₄ (for the most common variety) |
| Color | Red, pink, orange, blue, purple |
| Hardness (Mohs) | 8 |
| Refractive Index | 1.718 |
| Specific Gravity | 3.6–4.0 |
| Luster | Vitreous |
| Cleavage | None |
| Fracture | Subconchoidal |
| Transparency | Transparent to translucent |
| Inclusions | Common inclusions include inclusions of other minerals, such as zircon or rutile |
Spinel is a hard and durable gemstone, making it ideal for use in rings and other jewelry. It is also stable under light and chemicals, but high heat can cause some colors to fade, especially in lighter tones.
Sardonyx
| Property | Value |
|---|---|
| Chemical Formula | SiO₂ (silicon dioxide) |
| Color | Alternating bands of red, orange, and white or black |
| Hardness (Mohs) | 6.5–7 |
| Refractive Index | 1.48–1.53 |
| Specific Gravity | 2.58–2.64 |
| Luster | Waxy to vitreous |
| Cleavage | None |
| Fracture | Uneven to conchoidal |
| Transparency | Translucent |
| Inclusions | Common, especially in dyed stones |
Sardonyx is a durable and stable gemstone, though it is softer than many other gems, and high heat can affect the color of dye-treated sardonyx. It is also susceptible to scratches and should be handled with care.
Symbolism and Metaphysical Beliefs
Peridot
Peridot has long been associated with positive energy, protection, and clarity. In ancient times, it was believed to ward off evil spirits and the terrors of the night. It was also used as a talisman for protection and strength.
Modern metaphysical beliefs associate peridot with healing, transformation, and emotional balance. It is often used in crystal healing to promote inner peace, reduce stress, and enhance self-esteem. Peridot is also believed to attract abundance and prosperity, making it a popular gemstone for those seeking financial success and personal growth.
Spinel
Spinel is believed to bring courage, confidence, and emotional clarity. It is associated with passion, love, and creativity, making it a popular gemstone for romantic jewelry. Spinel is also believed to enhance communication and self-expression, helping individuals to speak their truth and assert themselves.
In some cultures, spinel is believed to protect against negative energy and to promote inner strength and resilience. It is also thought to enhance intuition and psychic abilities, making it a valuable tool for spiritual growth and exploration.
Sardonyx
Sardonyx is believed to bring courage, happiness, and clear communication. It is associated with strength, stability, and emotional balance, making it a popular gemstone for those seeking relationship harmony and partnership success.
In ancient times, sardonyx was believed to protect warriors and soldiers in battle, and it was also used as a talisman for protection and good fortune. It is also believed to enhance self-confidence and assertiveness, helping individuals to stand up for themselves and take action.
Care and Cleaning
Peridot
Peridot is a relatively soft gemstone with a Mohs hardness of 6.5–7, which means it is easily scratched and can be damaged by acids and acidic perspiration. It is also susceptible to thermal shock, which can cause it to crack or break.
Cleaning peridot should be done carefully. Avoid using steam or ultrasonic cleaners, as these can damage the stone. Instead, use warm soapy water and a soft-bristle brush to gently clean the gem. After cleaning, rinse the gem thoroughly and dry it with a soft cloth.
Peridot should be stored separately from harder gemstones to prevent scratches and abrasions.
Spinel
Spinel is a hard and durable gemstone with a Mohs hardness of 8, making it ideal for use in rings and other jewelry. It is also stable under light and chemicals, so it can be cleaned using ultrasonic or steam cleaners.
However, if the spinel has fractures or inclusions, ultrasonic and steam cleaning may not be recommended, as they can exacerbate existing damage. Warm soapy water is always a safe and effective cleaning method.
Spinel should be stored separately from acidic or abrasive substances, and it should be handled with care to avoid scratches and abrasions.
Sardonyx
Sardonyx is a relatively soft gemstone with a Mohs hardness of 6.5–7, making it susceptible to scratches and abrasions. It is also often dyed, and high heat can affect the color of dye-treated sardonyx.
Cleaning sardonyx should be done carefully. Avoid using steam or ultrasonic cleaners, as these can damage the stone or cause the dye to fade. Instead, use warm soapy water and a soft-bristle brush to gently clean the gem.
Sardonyx should be stored separately from harder gemstones to prevent scratches and abrasions.
Conclusion
The August birthstone ring is a unique and meaningful piece of jewelry that can feature one of three remarkable gemstones—peridot, spinel, or sardonyx. Each of these gemstones has its own distinct geological origin, historical significance, and cultural symbolism, making them fascinating and valuable additions to any jewelry collection.
Peridot, with its vibrant green color and cosmic origins, is a gem that has been treasured for thousands of years. Spinel, once mistaken for ruby and sapphire, has gained increasing recognition for its brilliance and versatility. Sardonyx, an ancient gemstone of layered chalcedony, has been used for carvings and seals for millennia.
Whether you are a gemstone enthusiast, a jewelry buyer, or a student of gemology, the August birthstones offer a rich and diverse world of beauty and meaning. By understanding their properties, history, and care requirements, you can make informed decisions and appreciate the enduring legacy of these remarkable gemstones.