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 many inclusions, so their toughness (resistance to breakage) is classified as generally poor. Emerald is a cyclosilicate.
Spinel is the magnesium/aluminium member of the larger spinel group of minerals. It has the formula MgAl
2O
4 in the cubic crystal system. Its name comes from the Latin word spinella, a diminutive form of spine, in reference to its pointed crystals.
Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminium oxide (α-Al2O3) with trace amounts of elements such as iron, titanium, cobalt, lead, chromium, vanadium, magnesium, boron, and silicon. The name sapphire is derived from the Latin word sapphirus, itself from the Greek word sappheiros (σάπφειρος), which referred to lapis lazuli. It is typically blue, but natural "fancy" sapphires also occur in yellow, purple, orange, and green colors; "parti sapphires" show two or more colors. Red corundum stones also occur, but are called rubies rather than sapphires. Pink-colored corundum may be classified either as ruby or sapphire depending on the locale. Commonly, natural sapphires are cut and polished into gemstones and worn in jewelry. They also may be created synthetically in laboratories for industrial or decorative purposes in large crystal boules. Because of the remarkable hardness of sapphires – 9 on the Mohs scale (the third-hardest mineral, after diamond at 10 and moissanite at 9.5) – sapphires are also used in some non-ornamental applications, such as infrared optical components, high-durability windows, wristwatch crystals and movement bearings, and very thin electronic wafers, which are used as the insulating substrates of special-purpose solid-state electronics such as integrated circuits and GaN-based blue LEDs. Sapphire is the birthstone for September and the gem of the 45th anniversary. A sapphire jubilee occurs after 65 years.
The mineral or gemstone chrysoberyl is an aluminate of beryllium with the formula BeAl2O4. The name chrysoberyl is derived from the Greek words χρυσός chrysos and βήρυλλος beryllos, meaning "a gold-white spar". Despite the similarity of their names, chrysoberyl and beryl are two completely different gemstones, although they both contain beryllium. Chrysoberyl is the third-hardest frequently encountered natural gemstone and lies at 8.5 on the Mohs scale of mineral hardness, between corundum (9) and topaz (8).
Tanzanite is the blue and violet variety of the mineral zoisite, caused by small amounts of vanadium. Tanzanite belongs to the epidote mineral group. Tanzanite is only found in Simanjiro District of Manyara Region in Tanzania, in a very small mining area approximately 7 km (4.3 mi) long and 2 km (1.2 mi) wide near the Mererani Hills.
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.
Trapiche emerald is a rare variety of the gemstone emerald, characterized by a six-arm radial pattern of usually black spokes separating areas of green emerald. If weathered, the black spokes may become light in color. Trapiche emerald is one of an assortment of trapiche or trapiche-type minerals. Others include trapiche ruby, sapphire, tourmaline, quartz, and chiastolite. The name comes from the Spanish term trapiche, a sugar mill, because of the resemblance of the pattern to the spokes of a grinding wheel. Emerald is a gem variety of the mineral beryl, and owes it distinctive green color to the presence of chromium and/or vanadium.
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.
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.
Aquamarine is a pale-blue to light-green variety of the beryl family, with its name relating to water and sea. The color of aquamarine can be changed by heat, with a goal to enhance its physical appearance. It is the birth stone of March.
FURA Gems is a private global mining company that produces colored gemstones: emeralds, rubies, and sapphires. Founded in 2017 by Dev Shetty, FURA has its headquarters in Dubai, United Arab Emirates, and operates mining subsidiaries in Colombia, Mozambique, and Australia. In 2021, the company managed approximately six million carats of Mozambican rubies and 300,000 carats of Colombian emeralds. In 2022, FURA Gems unveiled the world's largest gem-quality ruby ever mined, which was sold by Sotheby's for $34.8 million in 2023.
