For centuries, a gemstone often mistaken for ruby has quietly captivated royalty and gem enthusiasts alike. Recently recognized as a modern August birthstone alongside peridot and sardonyx, spinel boasts a rich history, stunning brilliance, and a chemical composition distinct from its more famous look-alike. This article delves into the fascinating world of spinel, exploring its geological origins, historical significance, gemological properties, and enduring appeal.
History and Lore
Spinel’s story is one of mistaken identity and eventual recognition. For a considerable period, particularly in historical jewelry, many stones identified as rubies were, in fact, spinels. This “great impostor,” as it has been called, adorned the crown jewels of numerous empires, its true nature remaining undiscovered until 1783 when it was differentiated from corundum, the mineral that comprises ruby and sapphire.
The confusion stemmed from the similar appearance and shared chromium impurities that contribute to the red coloration in both gemstones. Some of the most celebrated “rubies” in royal collections, including those belonging to royalty, were later identified as spinels. This historical misidentification doesn’t diminish spinel’s value; rather, it adds to its mystique and underscores its inherent beauty.
The American Gem Trade Association (AGTA) and Jewelers of America officially designated spinel as an August birthstone in response to a growing demand from gem enthusiasts for an expanded birthstone list. This addition, occurring only the third time in over a century that the modern birthstone list was amended, acknowledges spinel’s historical significance and vibrant colors.
Geological Formation and Sources
Spinel forms under unique geological conditions, often found in metamorphic rocks and alluvial deposits. It is composed of magnesium aluminum oxide, differing chemically from ruby’s aluminum oxide composition. While peridot is found in volcanic lava and even meteorites, spinel’s origins are typically associated with the earth’s mantle.
Historically, some of the finest spinels originated from Myanmar (Burma), producing intensely red varieties rivaling rubies in color. Vietnam also boasts historic gemstone mines yielding exceptional spinel specimens. More recent discoveries in Tanzania, in 2007, have captivated collectors with pinkish, orangy-red, purple, and blue spinel hues. Additional sources include San Carlos Apache India and Pakistan for peridot. Spinel’s presence in these diverse locations highlights its varied geological formation processes.
Gemological Properties
Spinel is a remarkably durable gemstone, registering an 8 on the Mohs scale of hardness. This hardness makes it suitable for a wide range of jewelry applications, including rings intended for everyday wear. While generally stable, the presence of fractures within a spinel can pose a problem during cleaning.
The gemstone exhibits good brilliance and sparkle, contributing to its aesthetic appeal. Spinel is stable when exposed to light and most chemicals. However, exposure to high heat can cause fading in some colors.
Spinel displays a wide spectrum of colors, ranging from vivid reds and blues to purple, pink, and even colorless varieties. The color is influenced by trace elements within the crystal structure. Red spinels, particularly those from Myanmar, are highly prized for their intense hues.
Here's a table summarizing key gemological properties:
| Property | Description |
|---|---|
| Chemical Formula | MgAl₂O₄ |
| Hardness (Mohs) | 8 |
| Stability | Stable to light and chemicals, sensitive to high heat |
| Colors | Red, blue, purple, pink, colorless |
| Luster | Vitreous (glass-like) |
Symbolism and Metaphysical Beliefs
Spinel is associated with revitalization, ambition, and eternal love. It is the traditional gemstone for celebrating the 22nd wedding anniversary. Peridot, the other August birthstone, symbolizes sunshine and new beginnings and is associated with the 16th wedding anniversary.
While specific metaphysical beliefs vary, spinel is often considered a grounding stone, promoting positive energy and emotional balance. Its vibrant colors are believed to inspire creativity and passion.
Care and Cleaning
Due to its hardness of 8 on the Mohs scale, spinel is generally a durable gemstone. Ultrasonic and steam cleaners can be used for cleaning, provided the stone is free of fractures. Warm, soapy water is always a safe and effective alternative. Regular cleaning will help maintain spinel’s brilliance and sparkle.
Conclusion
Spinel, once overshadowed by its ruby counterpart, has rightfully earned its place as a celebrated August birthstone. Its rich history, diverse colors, and durable nature make it a compelling choice for jewelry enthusiasts and collectors. From adorning royal crowns to captivating modern gem lovers, spinel’s story is a testament to the enduring beauty and allure of this remarkable gemstone. Its recent recognition as a birthstone ensures that spinel will continue to shine for generations to come.