This is a List of emeralds by size.

Emeralds

Emerald Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium or sometimes vanadium.Hurlbut, Cornelius S. Jr. and Kammerling, Robert C. (1991) ''Gemology'', John Wiley & Sons, New York, p. ...

is a

gemstone A gemstone (also called a fine gem, jewel, precious stone, or semiprecious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis lazuli, opal, ...

and a variety of the

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ...

beryl Beryl ( ) 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 met ...

(Be₃Al₂(SiO₃)₆) colored

green Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 nm. In subtractive color systems, used in painting and color printing, it is created by a c ...

by trace amounts of

chromium Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium metal is valued for its high corrosion resistance and ha ...

and sometimes

vanadium Vanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer ( pass ...

. Beryl has a

hardness In materials science, hardness (antonym: softness) is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. In general, different materials differ in their hardness; for example har ...

of 7.5–8 on the

Mohs scale The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by th ...

. Most emeralds are highly included, so their toughness (resistance to breakage) is classified as generally poor. Emerald is a

cyclosilicate Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, silica (silicon dioxide, ) is usually cons ...

. Emeralds in antiquity were mined in

Egypt Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Medite ...

at locations on Mount Smaragdus since 1500 BCE, and India, and Austria since at least the 14th century CE. 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. 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. Emerald production in Colombia has increased drastically in the last decade, increasing by 78% from 2000 to 2010. The three main emerald mining areas in Colombia are

Muzo Muzo () is a town and municipality in the Western Boyacá Province, part of the department of Boyacá, Colombia. It is widely known as the world capital of emeralds for the mines containing the world's highest quality gems of this type. Muzo ...

, Coscuez, and

Chivor 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 and Chivor is located at from the department capital Tunja. Economic ac ...

. 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 responsible for 25-30% of the world's production of gem-quality stones. In 2019 Kagem emerald mine produced 42.4 million carats of emeralds. 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.

Notable emeralds

Bibliography

Notes References * * * - Total pages: 240 * * - Total pages: 352 * * * {{Gemstones

Emeralds Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium or sometimes vanadium.Hurlbut, Cornelius S. Jr. and Kammerling, Robert C. (1991) ''Gemology'', John Wiley & Sons, New York, p. ...

Emeralds

Notable emeralds

See also

Bibliography