August, the month of summer's final flourish, is distinguished by a rare and fortunate privilege in the world of birthstones: it is associated with not one, but three gemstones. Peridot, spinel, and sardonyx each offer a unique blend of beauty, symbolism, and historical significance. These stones have captivated civilizations for millennia, from the ancient Egyptians to the Roman emperors, and continue to be cherished for their enduring charm and spiritual resonance.
This article explores the three August birthstones in depth, examining their geological origins, historical uses, cultural symbolism, and modern relevance. Drawing from a range of authoritative sources, it presents a comprehensive overview of each gemstone, offering insights into their properties, meanings, and care. Whether you are an August-born individual, a gemstone collector, or simply someone fascinated by the interplay between nature and human history, this article will guide you through the rich tapestry of these remarkable stones.
History and Lore
The August birthstones—peridot, spinel, and sardonyx—have long been interwoven with human culture and mythology. While each stone has its own unique history, their stories are united by themes of protection, power, and prosperity.
Peridot: The Sun's Gift
Peridot is one of the oldest known gemstones, with a history stretching back thousands of years. Ancient Egyptians referred to it as the "gem of the sun," and it was believed to be formed from the tears of Ra, the sun god. The island of Zabargad in the Red Sea was a primary source of peridot in ancient times and is still known today for its deposits of the stone. The Egyptians used peridot in jewelry and amulets, often to ward off nightmares and promote good health.
During the Middle Ages, peridot was widely used in religious artifacts. One of the most notable examples is the Shrine of the Three Holy Kings in Cologne Cathedral, which was believed to be adorned with emeralds but is now known to contain peridot. This misidentification was common due to the stone’s vibrant green color, which closely resembles that of emerald.
In addition to its historical significance, peridot has been associated with various spiritual and protective properties. It was believed to bring happiness, strength, and prosperity to its wearer. Some cultures even thought it could cure illness and bring clarity of thought. Today, peridot remains a popular choice for jewelry and is often given as a gift for the sixteenth wedding anniversary.
Spinel: The Overlooked Gem
Spinel has a more recent history but is no less intriguing. Often mistaken for ruby and other precious gems, spinel was historically undervalued despite its vibrant colors and brilliance. The most famous example of this misidentification is the “Black Prince’s Ruby,” which is actually a large red spinel. It has been part of the British Crown Jewels since the 14th century.
Spinel was used by royalty and nobility in various cultures, particularly in India and the Middle East, where it was prized for its fiery colors and durability. Its name is derived from the Latin word “spinella,” meaning “little thorn,” a reference to the gem’s sharp, pointed crystal structure.
In the modern era, spinel has gained renewed appreciation as a gemstone alternative to ruby and sapphire. Its wide range of colors—including red, pink, orange, purple, blue, and black—makes it highly versatile in jewelry design. Spinel is also considered to have energetic properties, such as promoting vitality and emotional balance. It is often used in chakra work, particularly for the heart and solar plexus chakras.
Sardonyx: The Stone of Strength and Protection
Sardonyx, a type of chalcedony, has a long and storied history dating back over 4,000 years. It is one of the oldest known birthstones and was widely used in ancient civilizations, including Egypt, Greece, and Rome. The stone is characterized by its distinct banding—typically red and white layers—though it can also appear in brown and yellow tones.
In ancient times, sardonyx was believed to offer protection and strength. It was often carved into amulets and seals, used for both personal protection and to authenticate documents and letters. The Romans associated sardonyx with Mars, the god of war, and believed it could enhance courage and discipline.
Sardonyx has also been linked to love and relationships. In some cultures, it was used in engagement rings to symbolize fidelity and loyalty. It was also thought to help in resolving conflicts and strengthening bonds between people.
Despite its historical significance, sardonyx has remained a relatively underappreciated gemstone in modern times. However, it is making a resurgence in the world of vintage and antique jewelry, where its earthy tones and classic design appeal to those seeking meaningful and durable adornments.
Geological Formation and Sources
Understanding the geological origins of the August birthstones helps to appreciate their rarity and beauty.
Peridot: From Earth's Mantle to Meteorites
Peridot is a gem variety of the mineral olivine and is formed under extreme heat and pressure, typically in the Earth's mantle. It is brought to the surface through volcanic activity, often found in lava flows or in meteorites. This makes peridot one of the few gemstones that can be sourced from outer space.
Major sources of peridot include the United States (especially Arizona and New Mexico), Myanmar, China, Pakistan, and Vietnam. The island of Zabargad in the Red Sea, where peridot was historically mined, is still an important source of the gem. Peridot is also found in meteorites, particularly in the Allende meteorite, which fell in Mexico in 1969.
Spinel: A Diverse and Durable Gem
Spinel is a mineral composed of magnesium aluminum silicate and is found in a wide range of colors due to the presence of different trace elements. It forms in both igneous and metamorphic rocks and is often found in association with other gemstones such as ruby and sapphire.
Significant sources of spinel include Myanmar (Burma), Sri Lanka, Afghanistan, and Vietnam. The Mogok Stone Tract in Myanmar is particularly known for producing high-quality red and pink spinels. Spinel is also found in Madagascar, Tanzania, and parts of Africa.
Sardonyx: A Banded Chalcedony
Sardonyx is a type of chalcedony, a form of quartz characterized by its fine-grained structure and waxy luster. It is formed through the slow deposition of silica-rich fluids in cavities or fissures in rocks. The banding in sardonyx is the result of alternating layers of different mineral compositions.
Sardonyx is primarily found in India, Brazil, and the United States. Rajasthan in India is a major source of sardonyx, particularly the red and white varieties. Brazil is also known for producing high-quality sardonyx, which is often used in cabochon form for jewelry and decorative objects.
Gemological Properties
The gemological properties of a stone—such as hardness, refractive index, and color—play a crucial role in determining its use and value in jewelry. Here is a detailed overview of the properties of the August birthstones.
Peridot
- Chemical Formula: (Mg,Fe)₂SiO₄
- Hardness (Mohs Scale): 6.5 to 7
- Color: Yellow-green to deep olive-green
- Refractive Index: 1.65 to 1.70
- Luster: Vitreous
- Transparency: Transparent to translucent
- Crystal System: Orthorhombic
- Cleavage: Perfect in two directions
Peridot is known for its vibrant green color, which is caused by the presence of iron. It has a moderate hardness and is relatively sensitive to heat and chemicals, so it requires careful handling and cleaning. Peridot is often cut into faceted gemstones or carved into cabochons.
Spinel
- Chemical Formula: MgAl₂O₄
- Hardness (Mohs Scale): 8
- Color: Red, pink, orange, purple, blue, black
- Refractive Index: 1.718 to 1.736
- Luster: Vitreous
- Transparency: Transparent to translucent
- Crystal System: Isometric
- Cleavage: None
Spinel is a durable gemstone with a high refractive index, giving it a brilliant sparkle. Its hardness makes it suitable for everyday wear in jewelry. The wide range of colors available in spinel makes it a popular choice for both classic and contemporary designs.
Sardonyx
- Chemical Formula: SiO₂ (quartz-based)
- Hardness (Mohs Scale): 6.5 to 7
- Color: Red, brown, white, yellow
- Refractive Index: 1.486 to 1.530
- Luster: Waxy
- Transparency: Translucent
- Crystal System: Trigonal
- Cleavage: None