Beryl is a mineral renowned for its diverse and captivating varieties, including the highly prized emerald and aquamarine. Composed of beryllium aluminium silicate with the chemical formula Be3Al2(SiO3)6, beryl exhibits a range of colors – green, blue, yellow, pink, and the exceptionally rare red – due to the presence of trace impurities. This article will explore the history, geological origins, gemological properties, and symbolism associated with beryl and its various forms, drawing solely from available sources.
History and Lore
The story of beryl stretches back to antiquity. The name “beryl” itself has a rich etymological history, originating from the Ancient Greek bḗryllos, which referred to various blue-green stones. This term was adopted via Old French and Latin, ultimately stemming from the Prakrit veruḷiya, potentially linked to towns in southern India like Belur or Velur. Historically, beryl was valued for its beauty and perceived properties. As early as the 13th century, colorless beryl, known as goshenite, was utilized in the creation of eyeglasses in Italy, as glass clarity was insufficient for lens production at the time. This practical application led to the German word for glasses, Brille, being derived from the term for beryl.
The modern English word "emerald" also traces its roots back through similar linguistic pathways from the Greek smaragdos, meaning "green gem." The red variety, once known as “bixbite,” was first formally described in 1904 from a locality in Utah, though this name is now discouraged due to potential confusion with another mineral. Marketing terms like “red emerald” are also prohibited by trade regulations.
Geological Formation and Sources
Beryl typically forms in pegmatites, which are coarse-grained igneous rocks, and in metamorphic rocks. Naturally occurring hexagonal crystals can reach substantial sizes, even several meters, though well-formed, terminated crystals are relatively uncommon.
Aquamarine, the blue to pale blue variety, is found in several locations worldwide. In the United States, deposits exist at the summit of Mount Antero in Colorado, as well as in New England and North Carolina pegmatites. Wyoming also yields aquamarine from the Big Horn Mountains, and Idaho has occurrences in the Sawtooth Range, though collection is restricted due to its wilderness area status. Brazil is a significant source, with mines in Minas Gerais, Espírito Santo, and Bahia. Additional sources include Colombia, Pakistan (Skardu), Madagascar, Russia, Namibia, Zambia, Malawi, Tanzania, and Kenya.
Emerald, the green variety colored by chromium and sometimes vanadium, is also sourced globally. Golden beryl and heliodor, ranging from pale yellow to brilliant gold, are similarly found in various locations. Goshenite, the colorless form, was originally discovered in Goshen, Massachusetts. Morganite, the pink variety, is a rarer gem. Red beryl, the most scarce, was initially identified in Utah.
Gemological Properties
Beryl exhibits several key gemological properties. It possesses a birefringence ranging from 0.0040 to 0.0070. Pleochroism, the display of different colors when viewed from different directions, is present, ranging from weak to distinct. Beryl does not typically exhibit ultraviolet fluorescence, although fracture-filling materials used to enhance emerald clarity may fluoresce. Morganite, however, displays weak violet fluorescence.
The color variations within beryl are directly linked to trace element inclusions. The pale blue of aquamarine is attributed to the presence of Fe2+ (ferrous iron). Fe3+ (ferric iron) produces golden-yellow hues, and the combination of both Fe2+ and Fe3+ results in a darker blue, as seen in maxixe aquamarine. Emerald’s green color is caused by approximately 2% chromium, with vanadium sometimes contributing. Golden beryl’s yellow color is due to Fe3+ ions, while morganite’s pink color is attributed to Mn2+ (manganous) ions. Red beryl’s color is caused by Mn3+ (manganic) ions.
Emeralds are generally brittle due to their high inclusion content. Goshenite, being colorless, can be irradiated to produce a range of colors – yellow, green, pink, blue, and intermediate shades – depending on the presence of impurities like calcium, scandium, titanium, vanadium, iron, and cobalt.
The following table summarizes key properties:
| Property | Value |
|---|---|
| Chemical Formula | Be3Al2(SiO3)6 |
| Birefringence | 0.0040–0.0070 |
| Pleochroism | Weak to distinct |
| Fluorescence | Generally none (except for some treatments/varieties) |
| Hardness | (Not specified in sources) |
Symbolism and Metaphysical Beliefs
While the provided sources do not detail extensive metaphysical beliefs associated with beryl, the vibrant colors of its varieties have historically been linked to emotional and psychological effects. The Orphic style of art, characterized by the use of vibrant colors, suggests a belief in the power of color to evoke emotions and sensations. The sources mention that certain colors, like those used in spring-themed attire, can evoke feelings of happiness and optimism. The selection of colors based on skin undertones also implies a belief in their ability to enhance one's appearance and mood.
Care and Cleaning
The sources do not provide specific care and cleaning instructions for beryl. However, given that emeralds are known to be brittle due to inclusions, it can be inferred that all beryl varieties should be handled with care to avoid damage.
Conclusion
Beryl represents a fascinating group of gemstones with a rich history, diverse geological origins, and captivating range of colors. From the ancient use of goshenite in eyeglasses to the prized beauty of emerald and aquamarine, beryl has held a significant place in human culture and adornment. The variations in color, attributed to trace element inclusions, contribute to the unique appeal of each beryl variety. Its continued presence in jewelry and gem collections worldwide underscores its enduring significance as a gemstone of beauty and historical importance.