Beryl: The Versatile Gemstone
Beryl, deriving its name from the ancient Greek word “beryllos,” was initially a term for all green gemstones. Over time, it evolved to represent the entire spectrum of beryl varieties. Beyond its ornamental value, beryl serves as the primary source of beryllium, a key component in crafting lightweight metal alloys known for their impressive tensile strength, hardness, and fatigue resistance. Notably, the emerald, a vibrant green member of the beryl family, stands tall among the four traditional precious gemstones.
In its purest form, beryl is colorless, known as goshenite. However, impurities lend beryl a rainbow of colors: from the serene blue to blue-green of aquamarine, the intense green of emerald, the sunny yellow of heliodor (often referred to as golden beryl), the rare red of bixbite, to the delicate pink of morganite.
Beryl predominantly forms in silica-rich granites and granite pegmatites, often accompanying minerals like quartz, feldspars, and muscovite. Within these pegmatites, beryl can manifest as aquamarine, heliodor, or morganite. Additionally, beryl appears in mica schists from metamorphic-hydrothermal deposits, resulting from the chemical interplay between pegmatites and neighboring basic rocks. The iconic green of emeralds emerges when the basic rock contains traces of chromium. Bixbite, or red beryl, is a rarity, typically discovered within rhyolite’s gas cavities.
Beryl deposits span the globe, from European nations like Norway, Austria, Germany, and Ireland to countries like Brazil, Colombia, Madagascar, Russia, South Africa, and Zambia. In the United States, beryl is mined in states including California, Colorado, Idaho, Maine, Connecticut, New Hampshire, North Carolina, South Dakota, and Utah, with Sweden being particularly known for morganite.
Properties and Enhancements
With a hardness rating of 7.5-8 on the Mohs scale, beryl boasts considerable durability. Some beryls, especially the dark blue ones, undergo radiation treatment, akin to the process used for blue topaz. Morganite and aquamarine might be heat-treated to intensify their color and eliminate any yellowish tints. Emeralds, on the other hand, are often subjected to oiling, a method that immerses the gem in colorless oil to mask inclusions.
Lab-Created and Simulants
The market offers lab-created versions of emeralds and aquamarines. Additionally, simulated emeralds, bearing a close resemblance in color to their natural counterparts, are also available.