August is unique among the months, possessing not one, but three recognized birthstones: peridot, sardonyx, and spinel. While sardonyx holds a historical connection to the month, modern birthstone charts prominently feature peridot and, more recently, spinel. This article will delve into the history, geological origins, gemological properties, and symbolism of these two prominent August birthstones, peridot and spinel, drawing exclusively from available sources.
History and Lore
The tradition of associating gemstones with specific months dates back to ancient times, originating with the twelve gemstones on the Breastplate of Aaron, as described in the Book of Exodus. These stones were linked to the twelve tribes of Israel and, subsequently, the zodiac signs and months of the year. While the initial August birthstone was sardonyx, with a history spanning over 4,000 years, the modern list expanded to include peridot and, in 2016, spinel.
Peridot’s history is marked by frequent misidentification. The gem was often confused with emerald and topaz, with the Red Sea island of Topazios – a source originally believed to yield topaz – actually producing significant quantities of peridot. Historical accounts suggest that Cleopatra’s famed emerald collection may have, in fact, contained a substantial amount of peridot. The Shrine of the Three Holy Kings in Cologne Cathedral features 200 carats of gems once thought to be emeralds, but now identified as peridot.
Spinel’s history is intertwined with that of ruby. For centuries, red spinel was often mistaken for ruby, particularly as both gems were found in the same mines. Many historical “rubies” in famous collections, including a large red stone in the British State Crown, were later discovered to be spinel. The gem was referred to as “mother of ruby” due to this frequent confusion, and varieties were given names like “ruby spinel” and “balas ruby.” It wasn’t until advancements in gemological practices allowed for accurate identification that spinel began to be recognized as a distinct and valuable gemstone.
Geological Formation and Sources
Peridot is formed under extreme conditions, originating in the Earth’s mantle and brought to the surface by volcanic activity. It can also be found in fallen meteorites, specifically Pallasite Meteorites, though these typically yield stones too small for jewelry use. The gem is composed of olivine, magnesium, and iron, with the amount of iron influencing its color and luster.
Spinel crystallizes in a cubic structure, similar to garnet and diamond, and often displays twinning crystals. Unlike ruby, which is dichroic (exhibiting different hues when viewed from different angles), spinel tends to be a consistent color throughout the stone. The sources for both gems are varied. While specific mining locations are not detailed in the provided sources, the text indicates both gems are found in locations where volcanic activity has occurred. The historical proximity of spinel and ruby deposits suggests shared geological origins in certain regions.
Gemological Properties
Peridot’s chemical formula is (Mg,Fe)2 SiO4. It is known for its yellowish-green to greenish-yellow color, earning it the nickname “sun gem.” Peridot exhibits a unique capacity to sparkle under both natural and artificial light, though it is distinct from emerald in its characteristics.
Spinel, while often red, occurs in a range of colors, including pink and blue. Blue spinels are often mistaken for sapphires. A key distinguishing feature between spinel and ruby is their crystal structure; spinel’s cubic structure commonly displays twinning crystals, while ruby does not.
The sources do not provide detailed gemological data such as refractive index, specific gravity, or clarity grading for either peridot or spinel. However, they do classify peridot as a semi-precious stone, while spinel is increasingly recognized as a gemstone of significant value, particularly as an alternative to ruby.
The following table summarizes the limited gemological information available from the sources:
| Gemstone | Chemical Formula | Color(s) | Nickname |
|---|---|---|---|
| Peridot | (Mg,Fe)2 SiO4 | Yellowish-green to greenish-yellow | "Sun Gem," "Evening Emerald" |
| Spinel | Not specified | Red, pink, blue, and others | "Mother of Ruby" |
Symbolism and Metaphysical Beliefs
The sources mention that spinel is sometimes referred to as a “stone of immortality.” While specific metaphysical beliefs are not extensively detailed, the historical association of both peridot and spinel with royalty and religious figures suggests a perceived power or significance. Peridot’s origin in volcanic lava and meteorites adds to its “mystic allure and power.” The association of the twelve birthstones with the tribes of Israel also imbues them with symbolic meaning rooted in religious tradition.
Care and Cleaning
The sources offer limited guidance on the care and cleaning of these gemstones. For both peridot and spinel, warm soapy water applied with a soft-bristle brush is recommended as the safest cleaning method. Ultrasonic and steam cleaners should be used with caution. This caution likely stems from the potential for damage due to inclusions or internal fractures within the stones.
Conclusion
Peridot and spinel represent a fascinating duality for those born in August. Peridot, with its ancient history and volcanic origins, offers a vibrant green hue and a connection to the sun. Spinel, long mistaken for ruby, has emerged as a gemstone in its own right, boasting a range of colors and a captivating history. The addition of spinel to the list of August birthstones in 2016 reflects a growing appreciation for this often-overlooked gem. Both stones offer unique beauty, historical significance, and symbolic meaning, making them cherished choices for those seeking a personal connection to their birth month.