Emeralds
Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium and sometimes vanadium. Beryl has a hardness of 7.5–8 on the Mohs scale. Most emeralds are highly included, [2] so their toughness (resistance to breakage) is classified as generally poor. Emerald is a cyclosilicate.
Emeralds in antiquity were mined in Egypt at locations on Mount Smaragdus since 1500 BCE, and India, and Austria since at least the 14th century CE. [3] The Egyptian mines were exploited on an industrial scale by the Roman and Byzantine Empires, and later by Islamic conquerors. Mining ceased with the discovery of the Colombian deposits; only ruins remain. [4]
Colombia is historically an important producer of emeralds, constituting 50–95% of the world production, with the number depending on the year, source and grade. [5] [6] [7] [8] Emerald production in Colombia has increased drastically in the last decade, increasing by 78% from 2000 to 2010. [9] The three main emerald mining areas in Colombia are Muzo, Coscuez, and Chivor. [10] Rare "trapiche" emeralds are found in Colombia, distinguished by ray-like spokes of dark impurities.
Zambia is the world's second biggest producer, with Kagem mine being the world's largest emerald mine [11] responsible for 25–30% of the world's production of gem-quality stones. [12] In 2019 Kagem emerald mine produced 42.4 million carats of emeralds. [13] The Zambian emerald sector is an important contributor of tax revenue to the Government.
Zambian emeralds were formed over 500 million years ago, they are geologically much older than emeralds from other origins. As a result, they differ in their formation, composition and key features. Zambian emeralds get their intense green colour from the presence of chromium, iron and beryllium, and they are often lacking in vanadium, resulting in a bluish-green, lively and often eye-clean emerald.
Beryl ( BERR-əl) is a mineral composed of beryllium aluminium silicate with the chemical formula Be3Al2Si6O18. Well-known varieties of beryl include emerald and aquamarine. Naturally occurring, hexagonal crystals of beryl can be up to several meters in size, but terminated crystals are relatively rare. Pure beryl is colorless, but it is frequently tinted by impurities; possible colors are green, blue, yellow, pink, and red (the rarest). It is an ore source of beryllium.
Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium or sometimes vanadium. Beryl has a hardness of 7.5–8 on the Mohs scale. Most emeralds have lots of material trapped inside during the gem's formation, so their toughness (resistance to breakage) is classified as generally poor. Emerald is a cyclosilicate.
Zambia is a developing country, and it achieved middle-income status in 2011. Through the first decade of the 21st century, the economy of Zambia was one of the fastest-growing economies in Africa, and its capital, Lusaka, the fastest-growing city in the Southern African Development Community (SADC). Zambia's economic performance has stalled in recent years due to declining copper prices, significant fiscal deficits, and energy shortages.
Tsavorite or tsavolite is a variety of the garnet group species grossular, a calcium-aluminium garnet with the formula Ca3Al2Si3O12. Trace amounts of vanadium or chromium provide the green color.
Harry Winston was an American jeweler. He donated the Hope Diamond to the Smithsonian Institution in 1958 after owning it for a decade. He also traded the Portuguese Diamond to the Smithsonian in 1963 in exchange for 3,800 carats of small diamonds.
The Gachalá Emerald, one of the most valuable and famous emeralds in the world, was found in 1967, in the mine called Vega de San Juan, located in Gachala, a town in Colombia, located 142 km (88 mi) from Bogota. Gachalá Chibcha means "place of Gacha." Presently the emerald is in the United States, where it was donated to the Smithsonian Institution by the New York City jeweler, Harry Winston.
The Chalk Emerald is a 37.82 carats (7.564 g) rectangular step-cut emerald, mined in Muzo, Colombia. It was one of many Colombian emeralds shipped to Mughal India by the Spanish in the 16th and 17th centuries. Ownership of the stone after its arrival is unrecorded until its sale by Jagaddipendra Narayan, the Maharaja of Koch Bihar, to a British gem broker in 1959. Jagaddipendra stated that the stone was formerly the centerpiece of an emerald and diamond necklace worn by his mother, Indira Devi, to various state functions.
Chivor is a town and municipality in the Eastern Boyacá Province, part of the Colombian department of Boyacá. The mean temperature of the village in the Tenza Valley is 18 °C (64 °F) and Chivor is located at 215 kilometres (134 mi) from the department capital Tunja. Economic activity includes emerald mining.
Gemstone irradiation is a process in which a gemstone is artificially irradiated in order to enhance its optical properties. High levels of ionizing radiation can change the atomic structure of the gemstone's crystal lattice, which in turn alters the optical properties within it. As a result, the gemstone's color may be significantly altered or the visibility of its inclusions may be lessened.
The Hooker Emerald Brooch is an emerald brooch designed by Tiffany & Co. The brooch is on display in the Janet Annenberg Hooker Hall of Geology, Gems, and Minerals at the Smithsonian Institution's National Museum of Natural History in Washington D.C., United States.
Gemfields Group Ltd is a British mining company incorporated in Guernsey and headquartered in London, United Kingdom, and is a supplier of coloured gemstones. The company specializes in the mining, processing and sale of coloured gemstones, in particular emeralds and rubies. The group sells rough, uncut gemstones and does not operate any cutting and polishing facilities. The company owns the Kagem emerald mine in Zambia and the Montepuez ruby mine in Mozambique. Gemfields produces around 25% of the world's emerald supply and around 50% of the world's ruby supply.
Emeralds are green and sometime green with a blueish-tint precious gemstones that are mined in various geological settings. They are minerals in the beryl group of silicates. For more than 4,000 years, emeralds have been among the most valuable of all jewels. Colombia, located in northern South America, is the country that mines and produces the most emeralds for the global market, as well as the most desirable. It is estimated that Colombia accounts for 70–90% of the world's emerald market. While commercial grade emeralds are quite plentiful, fine and extra fine quality emeralds are extremely rare. Colombian emeralds over 50 carat can cost much more than diamonds of the same size.
The Las Pavas, also called La Pava, is a Colombian emerald mining area that is neighboring Colombia's largest emerald mine, Puerto Arturo. It is located 200 kilometres (120 mi) northwest of the capital Bogotá in the western emerald belt of Muzo, and about 235 kilometres (146 mi) west of Chivor, which is in the eastern emerald belt. The mining area spans the municipalities Quípama and Muzo.
Abdoulaye "Gounass" Ndiaye is a Senegalese businessman and entrepreneur based in Kitwe, Zambia.
The Allison and Roberto Mignone Halls of Gems and Minerals are a series of exhibition halls at the American Museum of Natural History on the Upper West Side in Manhattan, New York City. The halls opened on June 12, 2021, as a complete redesign of their predecessors, the Harry Frank Guggenheim Hall of Gems and Minerals and Morgan Memorial Hall of Gems. The halls feature thousands of rare gems, mineral specimens and pieces of jewelry.
Morganite is an orange or pink variety of beryl and is also a gemstone. Morganite is mined in Brazil, Afghanistan, Mozambique, Namibia, the United States, and Madagascar.
The Lion of Merelani is a tsavorite gemstone from Tanzania that is in the collection of the National Museum of Natural History of the Smithsonian Institution in Washington, DC. The gemstone weighs 116.76 carats, has 177 facets, and is an intense green color. It was donated in the memory of Campbell R. Bridges, the gemologist who discovered tsavorite, who was murdered in 2009. It is the largest known tsavorite gemstone and the largest fine gemstone ever to be cut and polished in the United States.
