Emerald
The emerald is the green variety of beryl, a cyclosilicate mineral of beryllium and aluminum with the chemical formula Be3Al2(SiO 3)6, which also contains small amounts of chromium and, in some cases, vanadium, which give it its characteristic green color. The specific weight ranges from 2.65 and 2.90 and has a hardness of 7.5 to 8 on the Mohs scale. Most emeralds are highly included, so their toughness (resistance to breakage) is classified as generally poor.
It is a highly valued gemstone. Already in antiquity, green colored stones, such as malachite, and variscite were highly appreciated. The emerald combines with its especially intense green color the property of being transparent or at least translucent, and its greater brilliance when polished. Its name, possibly Persian, means green stone and its hue has given its name to the color emerald green.
Technically, emerald is a variety of beryl whose color is due to the presence of chromium and/or vanadium. Its value as a gem depends critically on its degree of transparency. Near opaque emerald is relatively common and found in many countries, but its value is currently very limited. Gem-quality emerald should be transparent, although it is almost never free of internal inclusions and blemishes, the so-called 'garden emerald', and is much rarer.
Gem-quality emeralds are found in great quantity in Colombia, as it is the world's leading producer of gem-quality emeralds. The trapiche emerald, which is found in some mines in Colombia, deserves special mention for its strange star shape due to the growth of the crystal in various directions. Its name comes from the toothed cylinder used in sugar mills to extract sugar from cane.
Other deposits are located in Brazil, especially in the state of Bahia. In this country, many low-quality emeralds are obtained, used without carving, associated with the host rock, as decoration material or for collecting. Small deposits in which gem material occasionally appears, but of interest especially to collectors, are found in the United States (especially in North Carolina).
In the Sikait-Zabara region, in Egypt, there are some emerald mines that were possibly exploited 3,500 years ago. With modern criteria, in view of the currently known deposits, the quality of the material is very low, but for centuries it was the main deposit of the Old World. Many years after the discovery of the emeralds, Cleopatra came to own these mines, as she felt a special fascination for these stones. [citation needed] In Africa, gem-quality emeralds are found in Zambia, especially in the Ndola district, as well as in Mozambique and Zimbabwe.
In Europe, the most important mines were those located in Russia, in the area of Yekaterinburg, in the Urals region. Generally its transparency is not very great. In some deposits they appear associated with chrysoberyl of the variety known as alexandrite. Deposits of the same type are found in Austria, in the Salzburg region, and in Spain, in Pontevedra.
In Asia, the most important deposits are in Afghanistan, in the province of Nuristan and in the Panjshir Valley. Those from India, in Tamil Nadu and Rajasthan, have been known since ancient times, although the quality of the material is mediocre. Emeralds, although very rarely of gem quality, have also been found in various Australian localities.
Symbolism
In the Middle Ages, it was a symbol of John the Apostle. For alchemists, it is the stone of Venus.
Superstition, since ancient times, has attributed miraculous virtues to this stone, such as preventing the symptoms of epilepsy and breaking when the disease had reached such a state of violence that it could not defeat it; to hasten her labor when they tied it to the thigh of the woman who was in the process of giving birth. Finally, the emerald powder cured dysentery and poisonous animal bites.
The peoples of the Manta Valley, in Ecuador, worshiped an emerald the size of an ostrich egg; They showed her on the days of the major festivals, and the Indians ran from everywhere to see her goddess and offer her other emeralds. The priests and caciques made the believers understand that the emerald mother was very happy, because she presented her daughters, managing to gather a large number of precious stones with this stratagem. When the Spanish expeditionaries conquered the region, it is said that they found all the daughters of the goddess, but the Indians knew how to hide the mother so well that her whereabouts have not yet been ascertained.
Famous Emeralds
- Esmeralda Gachalá: A 171.6 g emerald (858 carats). It was found in 1967 in the Vega de San Juan mine in the municipality of Gachalá of the department of Cundinamarca, Colombia.
- Esmeralda Fura: It is 2.2 kg (11 000 carats), it is the second largest carved emerald in the world, it was owned by Victor Carranza.
- Esmeralda Theodora: It is 11.4 kg (57 500 carats), it is the largest carved emerald in the world, owned by Regan Reaney, a rare gem dealer in Canada.
- Esmeralda Tena: Of 400 g (2000 carats), it has dark intensity, butterfly green, which makes it more valuable, much more valuable than the emerald that belonged to the Russian empress Catalina la Grande, and which was finished in Christie's of New York for two million dollars, this also property of Carranza.
- Esmeralda Catalina la Grande: An emerald of an approximate weight 4693 carats and 2200 g. It was found in 2010 in the Muzo mine in the municipality of Muzo of the department of Boyacá, Colombia.