For centuries, spinel has been a gemstone of distinction, often mistaken for its more famous cousin, ruby. Now recognized as a birthstone for August, alongside peridot and sardonyx, spinel boasts a rich history, captivating colors, and remarkable durability. This article delves into the geological origins, historical significance, gemological properties, and modern appreciation of this often-overlooked gem.
History and Lore
Spinel’s story is one of mistaken identity and eventual recognition. For a considerable period, red spinels were misidentified as rubies, adorning the crowns and jewels of powerful empires. Many historically significant “rubies” are, in fact, spinels. The 352.5-carat Timur Ruby, presented to Queen Victoria in 1851 and now part of the British Crown Jewels, is a prime example. Similarly, the 398.72-carat spinel within Russia’s Great Imperial Crown and the red spinels featured in the Imperial Crown of Austria were once believed to be rubies. Even the world’s largest known spinel, the 500-carat Samarian Spinel, part of the Iranian Crown Jewels, carries a legendary tale of being part of the biblical golden calf.
The distinction between spinel and ruby wasn’t definitively established until a few hundred years ago, highlighting the challenges faced by early mineralogists. This historical confusion only adds to spinel’s allure, connecting it to centuries of royal power and intrigue. The gemstone is also associated with the 22nd wedding anniversary.
Geological Formation and Sources
Spinel forms under intense heat and pressure, often found in metamorphic rocks and alluvial deposits. While historically sourced from Myanmar, Vietnam, and Tajikistan, significant deposits have been discovered in Tanzania in recent years, yielding spinels in a range of colors, including pinkish-red, orangy-red, purple, and blue. Peridot, the other August birthstone, is found in locations such as San Carlos Apache, India, and Pakistan. Spinel’s formation alongside other gems contributes to its occasional discovery in the same mining regions as ruby and sapphire.
Gemological Properties
Spinel’s chemical composition varies depending on its color, with chromium contributing to red and pink hues, a combination of iron and chromium causing orange and purple shades, iron producing violet to blue colors, and cobalt creating the most vibrant blues. The gemstone typically measures 7.5 to 8 on the Mohs scale of hardness, making it a durable choice for jewelry, suitable for everyday wear. Synthetic spinel, known for its durability, has been used in “birthstone” jewelry for decades as an imitation stone and also finds application in heat-resistant coatings for tools.
The following table summarizes key gemological properties:
| Property | Description |
|---|---|
| Hardness (Mohs) | 7.5 - 8 |
| Color | Red, pink, purple, blue, orange, colorless |
| Luster | Vitreous (glass-like) |
| Crystal System | Cubic |
| Refractive Index | Varies with composition |
Color Variations and Their Causes
The diverse range of spinel colors is a result of trace elements within the stone’s structure. Chromium is responsible for the vibrant reds and pinks, while a combination of iron and chromium produces orange and purple hues. Iron alone can create violet to blue spinels, and the presence of cobalt results in the most intense and sought-after blue shades. This variety in color contributes to spinel’s appeal as a gemstone, offering alternatives to ruby and sapphire.
Symbolism and Metaphysical Beliefs
Spinel is revered for symbolizing revitalization, ambition, and eternal love. Its formation under extreme conditions is thought to imbue it with qualities of courage and resilience. The gemstone is considered a powerful stone for overcoming challenges and fostering positive change. While specific metaphysical beliefs vary, spinel is generally associated with energy, passion, and a renewed sense of purpose.
Spinel in Jewelry
Spinel necklaces are available in a variety of colors, from delicate pinks to vibrant reds, and are often chosen as an exquisite alternative to rubies or sapphires. Both spinel and peridot, with a toughness of 8 on the Mohs scale, are remarkably durable and well-suited for daily wear. Contemporary and classic designs showcase the brilliance and radiance of spinel, making it a versatile gemstone for various jewelry styles. Custom-made spinel jewelry is also available, allowing individuals to create unique pieces tailored to their preferences.
Care and Cleaning
Due to its hardness of 8 on the Mohs scale, spinel is typically a durable gem for all types of jewelry. Spinel is stable when exposed to light and chemicals. However, high heat can cause some colors to fade. For cleaning, ultrasonic and steam cleaners can be used, but caution should be exercised if the stone contains fractures. Warm soapy water is always a safe and effective alternative for maintaining spinel’s brilliance.
Conclusion
Spinel, once overshadowed by its ruby counterpart, has emerged as a celebrated gemstone in its own right. Its captivating colors, historical significance, and remarkable durability make it a compelling choice for jewelry enthusiasts and collectors alike. As a recognized birthstone for August and a symbol of revitalization and eternal love, spinel continues to captivate and inspire, solidifying its place in the world of gemstones.