Blue gemstones have captivated humanity for millennia, symbolizing tranquility, devotion, and, historically, status. From the ancient Egyptians creating the first synthetic blue pigment to the reverence for blue hues in religious art, the allure of these stones is deeply ingrained in human culture. While sapphire often dominates discussions of blue gems, a diverse range of options exists, particularly when considering birthstone associations. This article will delve into the world of blue gemstones, focusing on tanzanite as a December birthstone, while also exploring other notable blue stones and their significance.
History and Lore of Blue Gemstones
The fascination with blue gemstones stretches back to antiquity. As early as 2500 BC, Egyptians were crafting “Egyptian blue,” the first synthetic pigment, demonstrating the value placed on this color. Throughout history, blue pigments were costly and therefore reserved for the elite and powerful. In many cultures, blue held sacred significance, adorning religious figures and objects. Ancient Greeks and Romans believed blue sapphires offered protection from harm and envy, while medieval clergy associated the color with Heaven. The Persian legend of the world resting on a giant sapphire, responsible for the sky’s hue, further illustrates the profound cultural impact of blue stones.
The use of blue gemstones extended beyond symbolism. Medieval Europeans attributed healing properties to sapphires, believing they could cure plague boils and eye diseases, and even act as an antidote to poison. Lapis lazuli’s pigment, “ultramarine,” was so valuable in the 12th century that it cost more than gold. Its accessibility later revolutionized Renaissance painting, particularly in Christian art.
Tanzanite: A Modern December Birthstone
Tanzanite is a relatively recent addition to the world of colored gemstones, yet its discovery in the 20th century created significant excitement within the gemological community. Identified as the mineral zoisite in 1962, the primary source of this December birthstone was located in the Merelani Hills of northern Tanzania in 1967. It was subsequently named tanzanite in honor of its country of origin.
Tiffany & Co. recognized tanzanite’s potential and became its primary distributor, launching a major advertising campaign in 1968. The gem’s vivid colors, high clarity, and potential for large cut stones quickly propelled it to popularity. Today, tanzanite is not only a December birthstone but also the traditional gem for the 24th wedding anniversary. The stone is described as “velvety” due to its deep, saturated color, which ranges from a pure rich blue to violet, with blue being the most valuable hue.
Geological Formation and Sources
Tanzanite is uniquely sourced, found commercially only in the Merelani Hills of northern Tanzania. The landscape surrounding the mines is characterized by grass-covered hillsides, scrub brush, and rocky soil, overshadowed by the snow-covered slopes of Mount Kilimanjaro. Mining operations range from small-scale to large, mechanized efforts, employing thousands of workers who extract the gem from mines dug over 100 meters deep.
While tanzanite’s origin is geographically limited, the world offers a variety of sources for other blue gemstones. Aquamarine is a beryl variety found in various locations, while larimar is exclusively sourced from the Dominican Republic. Benitoite, one of the rarest blue gems, is found only in a single California mine, producing around 300 carats per year. Turquoise, historically obtained through Turkish trade routes, is found in various locations globally.
Gemological Properties of Blue Gemstones
The world of blue gemstones encompasses a wide range of properties. Aquamarine, a variety of beryl, registers a 5 on the Mohs hardness scale. Azurite, known for its rich blue color, can weather into green malachite, sometimes forming combinations known as azurmalachite. Benitoite, a rare gem, exhibits a fiery sparkle exceeding that of diamond, despite being more affordable.
Here’s a table summarizing the properties of some of the discussed blue gemstones:
| Gemstone | Chemical Composition | Hardness (Mohs) | Notable Characteristics |
|---|---|---|---|
| Aquamarine | Be₃Al₂Si₆O₁₈ | 7.5 - 8 | Light to deep blue/blue-green, often heat-treated |
| Tanzanite | Ca₂Al₃(SiO₄)₃(OH) | 6.5 - 7 | Deep blue to violet, known for its “velvety” appearance |
| Benitoite | BaTiSiO₅ | 6 - 6.5 | Sapphire blue, violet-blue, or colorless, rare |
| Turquoise | CuAl₆(PO₄)₄(OH)₈·4H₂O | 5 - 6 | Opaque, greenish-blue with veining |
Blue topaz, a more abundant and affordable alternative to tanzanite and blue sapphire, comes in several shades, often treated to enhance color. London Blue topaz is a deep grayish-blue, Swiss Blue is a light neon blue, and Sky Blue is a paler blue to greenish-blue. Blue chalcedony, another option, is often artificially tinted to achieve a desired hue.
Symbolism and Metaphysical Beliefs
Blue gemstones are often associated with tranquility, honest communication, and devotion. As healing stones, they are believed to increase patience, soothe anxiety, and promote healthy, trusting relationships. These beliefs stem from historical and cultural associations, where blue was considered a sacred color and attributed with protective and healing powers.
The symbolism extends to specific stones. Sapphire, for example, traditionally symbolizes sincerity, truth, faithfulness, and nobility. Lapis lazuli was used in Mayan sacrifices and revered in Christian art, highlighting its spiritual significance. Each gemstone carries its own unique lore, adding to the mystique and appeal of these natural treasures.
Care and Cleaning
The appropriate care for a blue gemstone depends on its hardness and composition. Aquamarine, with a hardness of 7.5-8 on the Mohs scale, is relatively durable and can be cleaned with warm, soapy water and a soft brush. Tanzanite, with a hardness of 6.5-7, is more susceptible to scratches and should be handled with care. Avoid ultrasonic cleaners and harsh chemicals when cleaning tanzanite.
Turquoise, being a softer stone (5-6 on the Mohs scale), requires gentle cleaning with a soft cloth and mild soap. Avoid prolonged exposure to sunlight and harsh chemicals, as these can affect its color. For more delicate stones like benitoite, professional cleaning is recommended. Regular cleaning and careful handling will help preserve the beauty and brilliance of any blue gemstone.
Beyond Tanzanite: A Diverse Palette of Blue
While tanzanite stands out as a December birthstone, the world of blue gemstones offers a remarkable diversity. From the vibrant hues of indicolite and paraiba tourmaline to the serene shades of aquamarine and the rarity of benitoite, there is a blue stone to suit every taste and preference. Other notable blue gems include azurite, blue chalcedony, chrysocolla, dumortierite, iolite, kyanite, lapis lazuli, larimar, moonstone, blue opal, blue pearls, pietersite, blue spinel, and blue zircon. Each stone possesses unique characteristics, making the exploration of blue gemstones a captivating journey.
Conclusion
Blue gemstones hold a special place in human history and culture, representing tranquility, devotion, and a connection to the natural world. Tanzanite, a relatively recent discovery, has quickly become a beloved December birthstone, celebrated for its vivid color and unique origin. However, the spectrum of blue gems extends far beyond tanzanite, offering a diverse palette of options, each with its own history, properties, and symbolism. Whether admired for their beauty, cherished for their metaphysical properties, or sought after for their rarity, blue gemstones continue to captivate and inspire.