August is a month distinguished by its rich selection of birthstones—three gemstones, each with a unique history, geological origin, and symbolic meaning. These gemstones—peridot, sardonyx, and spinel—have captivated gem lovers for centuries, offering a diverse range of colors and properties. From the vibrant green of peridot to the deep reds of spinel and the banded beauty of sardonyx, August’s birthstones reflect both the earth’s natural wonders and the cultural traditions that have cherished them through time. This article explores the origins, properties, and significance of each gemstone, offering an in-depth guide for gemstone enthusiasts, jewelry collectors, and those born in August.
History and Lore
The tradition of associating gemstones with birth months dates back to ancient civilizations. One of the earliest references is the Breastplate of Aaron, described in the Book of Exodus, where twelve gemstones were said to represent the twelve tribes of Israel. Over time, these associations evolved into the modern concept of birthstones, which began to be formalized in the 19th and 20th centuries.
August originally had only sardonyx as its designated birthstone. Sardonyx has a long and storied history, with evidence of its use dating back over 4,000 years. The ancient Greeks and Romans revered this gemstone, using it in amulets, cameos, and seals. Sardonyx was believed to bring strength, courage, and protection, and it was especially valued by warriors who believed it enhanced communication and brought victory in battle.
In 1912, peridot was added as a second August birthstone by the National Association of Jewelers (now Jewelers of America). This addition was partly due to the frequent confusion between peridot and other green gems like topaz and emerald. One notable historical example is the Shrine of the Three Holy Kings in Cologne Cathedral, which was once thought to contain emeralds but was later found to be decorated with peridot.
In 2016, the birthstone list for August was further expanded with the addition of spinel by the Jewelers of America and the American Gem Trade Association. This move aimed to recognize spinel’s beauty and versatility, especially as a more affordable alternative to ruby and sapphire. Spinel had long been mistaken for these more famous gems due to its similar color and brilliance, but its unique crystal structure and affordability made it an ideal addition to the August lineup.
Today, August is one of only two months (the other being June) to have three official birthstones, offering a broader selection of gemstones that reflect different styles and preferences.
Geological Formation and Sources
Each of the August birthstones has a unique geological origin and source, reflecting the diverse ways in which gemstones are formed and mined.
Peridot
Peridot is the gem-quality form of the mineral olivine, and it is known for being formed under extreme conditions. It can be found in hardened lava that carried it from deep within the Earth’s mantle. This means that peridot can be found in volcanic rocks, where it was brought to the surface by magma activity. Peridot is also found in meteorites, making it one of the few gemstones that have origins beyond Earth.
The most notable sources of peridot include Zabargad Island (also known as St. John’s Island) in the Red Sea, Arizona in the United States, Sri Lanka, and Mali. Zabargad Island, in particular, has been a significant source of peridot for centuries and is often considered the traditional source of this gemstone.
Sardonyx
Sardonyx is a type of chalcedony, a microcrystalline variety of quartz. It is characterized by its banded patterns, which typically feature a reddish-brown or orange sard base with white or pale pink onyx bands. The formation of sardonyx occurs in sedimentary rock deposits, where silica-rich water seeps through the rock and deposits layers of quartz over time.
Historically, sardonyx was mined in India, Egypt, and Ethiopia, but today the primary sources include Brazil, Indonesia, and Nepal. The Roman Empire was a major consumer of sardonyx, using it for cameos and seals, and it remains a popular gemstone for jewelry and decorative objects.
Spinel
Spinel is a oxide mineral with a hexagonal crystal structure. It is formed in mafic igneous rocks, which are rich in iron and magnesium, and it is often found in metamorphic rocks as well. Spinel is known for its wide range of colors, including red, pink, blue, purple, and black, depending on the trace elements present in the crystal.
Historically, spinel was found in the Ural Mountains of Russia, where it was often mistaken for ruby. The most famous example is the "Black Prince’s Ruby", a large red gemstone set in the British Imperial State Crown, which is actually a spinel. Other notable sources include Afghanistan, Myanmar, Vietnam, and Brazil. In 2016, when spinel was officially added as an August birthstone, it marked a shift toward recognizing lesser-known but beautiful gemstones.
Gemological Properties
Each of August’s birthstones has unique physical and optical properties that distinguish it from other gemstones. Understanding these properties is essential for both gemologists and jewelry buyers, as they influence the stone’s durability, appearance, and care requirements.
Peridot
- Chemical Formula: (Mg,Fe)₂SiO₄
- Color: Ranges from yellow-green to greenish-yellow, with the most valuable stones exhibiting a vibrant lime-green hue.
- Hardness: 6.5–7 on the Mohs scale, which means it is relatively soft and can be scratched by harder materials like quartz or topaz.
- Luster: Vitreous (glassy)
- Refractive Index: 1.65–1.70
- Cleavage: Perfect in one direction, making it more susceptible to breakage if struck at a sharp angle.
- Transparency: Typically transparent to translucent
- Cut: Most commonly cut as a faceted gemstone, with round, oval, and cushion cuts being popular choices.
Peridot’s color is due to the presence of iron in its crystal structure, and it is one of the few gemstones that does not change color under different lighting conditions. Its vibrant green hue is unique and highly desirable, especially in high-quality stones.
Sardonyx
- Chemical Formula: SiO₂ (silicon dioxide)
- Color: Characterized by banded patterns, typically featuring a reddish-brown or orange sard base with white or pale pink onyx bands.
- Hardness: 6.5–7 on the Mohs scale, similar to peridot.
- Luster: Waxy to vitreous
- Refractive Index: 1.48–1.53
- Cleavage: No cleavage, but it can be brittle and prone to chipping.
- Transparency: Translucent to opaque
- Cut: Most commonly cut as a cabochon for cameos and seals, or as a faceted gemstone in oval or cushion cuts.
Sardonyx’s banded appearance is due to the alternating layers of sard (a reddish-brown chalcedony) and onyx (a white or pale pink chalcedony). The clarity and sharpness of the bands are important factors in determining the quality of a sardonyx gemstone.
Spinel
- Chemical Formula: MgAl₂O₄
- Color: Available in a wide range of colors, including red, pink, blue, purple, and black.
- Hardness: 8 on the Mohs scale, making it harder and more durable than peridot and sardonyx.
- Luster: Vitreous (glassy)
- Refractive Index: 1.718–1.834
- Cleavage: No cleavage, making it more resistant to breakage.
- Transparency: Typically transparent
- Cut: Most commonly cut as a faceted gemstone, with round, cushion, and oval cuts being popular choices.
Spinel’s brilliance and fire are comparable to those of ruby and sapphire, and it is often used as a more affordable alternative. High-quality red spinel is particularly sought after, as it can closely resemble ruby in appearance.
Symbolism and Metaphysical Beliefs
Each of the August birthstones carries its own symbolic meaning and has been associated with metaphysical properties in various cultures and traditions.
Peridot
Peridot has long been associated with positive energy and emotional balance. Ancient cultures believed that peridot could ward off negativity and promote inner peace. It was also thought to bring prosperity and abundance, making it a popular gemstone among merchants and travelers.
In medieval Europe, peridot was believed to be a stone of protection, especially against nightmares and negative dreams. It was often worn as a protective amulet, and it was also used in healing rituals to treat ailments related to the liver and digestive system.
Today, peridot is often used in jewelry and meditation practices, where it is believed to enhance clarity of thought and encourage optimism. It is also associated with love and friendship, making it a meaningful gift for those born in August.
Sardonyx
Sardonyx has been revered for its protective and strengthening properties. In ancient times, it was believed to enhance courage, communication, and victory in battle, and it was often worn by soldiers and warriors as a protective talisman.
It is also associated with self-confidence and determination, making it a popular stone for those who want to overcome challenges and achieve their goals. Sardonyx is believed to help control emotions and reduce anger, promoting calmness and rational thinking.
In modern metaphysical practices, sardonyx is used to enhance willpower and discipline, and it is often recommended for students, professionals, and public speakers who need to stay focused and confident. It is also believed to attract good luck and success, making it a popular stone for those seeking new opportunities.
Spinel
Spinel is a relatively modern gemstone in the realm of metaphysical beliefs, but it has quickly gained popularity for its energetic and protective properties. Red spinel, in particular, is associated with passion, energy, and vitality, and it is believed to stimulate the heart and circulatory system.
Spinel is also thought to enhance emotional healing and provide comfort during difficult times. It is believed to help release emotional blockages and promote inner strength, making it a valuable stone for those undergoing emotional or physical healing.
In addition, spinel is associated with clarity and intuition, helping individuals make clear and wise decisions. It is also believed to attract love and harmony, making it a meaningful gemstone for romantic relationships.
Care and Cleaning
Proper care and cleaning are essential to maintaining the beauty and longevity of August birthstone jewelry. Each gemstone has specific care requirements based on its hardness, cleavage, and sensitivity to heat and chemicals.
Peridot
Due to its relatively low hardness (6.5–7 on the Mohs scale) and perfect cleavage, peridot requires careful handling to avoid scratches and breakage. It is not recommended for everyday wear, especially in rings and bracelets, where it is more likely to be subjected to impact or abrasion.
- Cleaning: Use warm soapy water and a soft-bristle brush to clean peridot. Avoid ultrasonic and steam cleaners, as these can cause shattering or damage due to the stone’s cleavage.
- Storage: Store peridot separately from harder gemstones to prevent scratching.
Sardonyx
Sardonyx is slightly more durable than peridot, with a hardness of 6.5–7 on the Mohs scale. However, it is still prone to chipping and cracking, especially along the banded areas where the stone is more brittle.
- Cleaning: Use warm soapy water and a soft-bristle brush to clean sardonyx. Avoid harsh chemicals and abrasive cleaners, as they can damage the stone’s surface.
- Storage: Store sardonyx in a soft pouch or separate compartment to prevent abrasions and chips.
Spinel
Spinel is the hardest of the August birthstones, with a hardness of 8 on the Mohs scale and no cleavage, making it more durable and resistant to damage.
- Cleaning: Spinel can be cleaned with warm soapy water, ultrasonic cleaners, or steam cleaners, as it is less sensitive to these methods.
- Storage: Store spinel with other durable gemstones, as it is less likely to be damaged by scratching or impact.
Conclusion
The August birthstones—peridot, sardonyx, and spinel—offer a rich and diverse selection of gemstones that reflect the natural beauty, historical significance, and symbolic meaning of this month. From the vibrant green of peridot to the banded elegance of sardonyx and the brilliant colors of spinel, each gemstone tells a unique story of geological formation, cultural tradition, and personal significance.
Whether worn as a jewelry piece, a protective amulet, or a meaningful gift, these gemstones continue to capture the imagination of gem lovers around the world. Understanding their properties, history, and care requirements allows for a deeper appreciation of their beauty and value, ensuring that they remain treasured possessions for generations to come.