Emerald
Emerald with host rock
General
Category	Beryl variety
Chemical formula	Beryllium aluminium silicate with chromium, Be3Al2(SiO3)6::Cr
Identification
Color	Green
Crystal habit	Hexagonal Crystals
Crystal system	Hexagonal
Cleavage	Poor Basal Cleavage (Seldom Visible)
Fracture	Conchoidal
Mohs Scale hardness	7. The Mineral beryl is a Beryllium Aluminium cyclosilicate with the Chemical formula Be3Al2(SiO36 A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Beryllium (bəˈrɪliəm is a Chemical element with the symbol Be and Atomic number 4 WikipediaNaming For the Artificial intelligence Androids of the 1990s Science fiction series Space Above and Beyond, see Silicate (AI Chromium (ˈkroʊmiəm is a Chemical element which has the symbol Cr and Atomic number 24 In Mineralogy, shape and size give rise to descriptive terms applied to the typical appearance or habit of Crystals The many terms used by mineralogists A crystal system is a category of Space groups which characterize Symmetry of structures in three dimensions with Translational symmetry in three directions Cleavage, in Mineralogy, is the tendency of crystalline materials to split along definite planes creating smooth surfaces of which there are several named types In the field of Mineralogy, fracture is a term used to describe the shape and texture of the surface formed when a Mineral is broken The Mohs scale of mineral hardness characterizes the scratch resistance of various Minerals through the ability of a harder material to scratch a softer material 5 - 8. 0
Luster	Vitreous
Refractive index	1. Lustre (or luster) is a description of the way light interacts with the surface of a Crystal, rock, or Mineral. The refractive index (or index of Refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves is reduced inside the medium 576 - 1. 582
Pleochroism	Distinct, Blue-Green/Yellow-Green
Streak	White
Specific gravity	2. Pleochroism is an Optical phenomenon in which grains of a rock appear to be different colors when observed at different angles under a Petrographic microscope. The streak (also called powder color) of a Mineral is the Color of the powder produced when it is dragged across an unweathered surface Specific gravity is defined as the ratio of the Density of a given solid or liquid substance to the density of water at a specific temperature and pressure typically 70 - 2. 78

Emeralds are a variety of the mineral beryl (Be₃Al₂(SiO₃)₆,) colored green by trace amounts of chromium and sometimes vanadium. A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific The Mineral beryl is a Beryllium Aluminium cyclosilicate with the Chemical formula Be3Al2(SiO36 Green is a Color, the perception of which is evoked by light having a spectrum dominated by energy with a Wavelength of roughly 520–570- nm. Chromium (ˈkroʊmiəm is a Chemical element which has the symbol Cr and Atomic number 24 Vanadium (vəˈneɪdiəm is a Chemical element that has the symbol V and Atomic number 23 ^[1] Beryl has a hardness of 7. Hardness refers to various properties of Matter in the Solid phase that give it high resistance to various kinds of shape change when Force 5 - 8 on the 10 point Mohs scale of mineral hardness. The Mohs scale of mineral hardness characterizes the scratch resistance of various Minerals through the ability of a harder material to scratch a softer material ^[2] Most emeralds are highly included, so their brittleness (resistance to breakage) is classified as generally poor. In mineralogy an inclusion is any material that is trapped inside a Mineral during its formation The word "emerald" comes from Latin smaragdus, via Greek smaragdos, its original source being a Semitic word or the Sanskrit word, marakata, meaning "emerald" or "green". Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly In Linguistics and Ethnology, Semitic (from the Biblical " Shem " Hebrew שם translated as "name" Arabic: ساميّ Sanskrit (sa संस्कृता वाक् saṃskṛtā vāk, for short sa संस्कृतम् saṃskṛtam) is a historical ^[3]

Properties determining value

Cut emeralds

Emeralds come in many shades of green and bluish green. There is a wide spectrum of clarity, dependent on the inclusions and fractures in the crystal. Clear stones with dark yet vibrant color command the highest prices. Almost all emeralds contain numerous flaws, cracks, and inclusions, which can negatively affect the clarity. These are given the name "jardin", from the French word for garden. The value of an emerald depends on cut, color, clarity, and carat. The carat is a unit of Mass used for measuring gems and Pearls Currently a carat is defined as exactly 200  mg (0 Currently the best emeralds come from the Muzo mine in Colombia. Colombia (kəˈlʌmbɪə officially the Republic of Colombia () is a country in northwestern South America. ^[4]

Treatments

Most emeralds are oiled as part of the post lapidary process, in order to improve their clarity. A lapidary (the word means "concerned with stones" is an Artisan who practices the craft of working forming and finishing stone, Mineral, Cedar oil, having a similar refractive index, is often used in this generally accepted practice. Cedar ( Cedrus) is a genus of Coniferous Trees in the Plant family Pinaceae. The refractive index (or index of Refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves is reduced inside the medium The U.S. Federal Trade Commission requires the disclosure of this treatment when a treated emerald is sold. The United States of America —commonly referred to as the The Federal Trade Commission ( FTC) is an independent agency of the United States government, established in 1914 by the Federal Trade Commission Act ^[5] The amount of oil entering an emerald microfissure is roughly equivalent to the size of a period (full stop) in print. A full stop or period (sometimes stop, full point, decimal point, or dot) is the Punctuation mark commonly placed at the The use of green-tinted oil is generally not considered acceptable by the gem trade.

Emerald localities

Emeralds in antiquity were mined by the Egyptians and in Austria, as well as Swat in northern Pakistan. Ancient Egypt was an Ancient Civilization in eastern North Africa, concentrated along the lower reaches of the Nile River in what is now Austria (Österreich ( officially the Republic of Austria (Republik Österreich Pakistan () officially the Islamic Republic of Pakistan, is a country located in South Asia, Southwest Asia, Middle East and ^[6][7]

A rare type of emerald known as a trapiche emerald is occasionally found in the mines of Colombia. Colombia (kəˈlʌmbɪə officially the Republic of Colombia () is a country in northwestern South America. A trapiche emerald exhibits a "star" pattern; it has raylike spokes of dark carbon impurities that give the emerald a six-pointed radial pattern. In Gemmology, an asterism is an Optical phenomenon displayed by some rubies, Sapphires and other gems (i It is named for the trapiche, a grinding wheel used to process sugarcane in the region. Sugarcane ( Saccharum) is a genus of 6 to 37 species (depending on taxonomic interpretation of tall perennial grasses (family Poaceae tribe Andropogoneae Colombian emeralds are generally the most prized due to their transparency and fire. Some of the most rare emeralds come from three main emerald mining areas in Colombia: Muzo, Coscuez, and Chivor. Fine emeralds are also found in other countries, such as Zambia, Brazil, Zimbabwe, Madagascar, Pakistan, India, Afghanistan and Russia. The Republic of Zambia (ˈzæmbɪə is a Landlocked country in Southern Africa. |utc_offset = -2 to -4 |time_zone_DST = BRST |utc_offset_DST = -2 to -5 |cctld See also Great Zimbabwe National Monument. For information about the March and June 2008 presidential elections see Zimbabwean presidential election Madagascar, or Republic of Madagascar (older name Malagasy Republic) is an Island nation in the Indian Ocean off the southeastern Pakistan () officially the Islamic Republic of Pakistan, is a country located in South Asia, Southwest Asia, Middle East and India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country Afghanistan /æfˈgænɪstæn/ officially the Islamic Republic of Afghanistan ( Pashto: د افغانستان اسلامي جمهوریت, Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending In the US, emeralds can be found in Gastonia, North Carolina. North Carolina ( is a state located on the Atlantic Seaboard in the southeastern United States In 1998, emeralds were discovered in the Yukon Territory, Canada. Yukon (ˈjuːkɒn is the westernmost and smallest of Canada's three territories. Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page ^[8]

Synthetic emerald

Emerald showing its hexagonal structure

Emerald is a rare and valuable gemstone and, as such, it has provided the incentive for developing synthetic emeralds. In Economics, an incentive is any factor (financial or non-financial that provides a motive for a particular course of action or counts as a reason for preferring one choice Both hydrothermal and flux-growth synthetics have been produced, and a method has been developed for producing an emerald overgrowth on colorless beryl. The first commercially successful emerald synthesis process was that of Carroll Chatham. Because Chatham's emeralds do not have any water and contain traces of vanadate, molybdenum and vanadium, a lithium vanadate flux process is probably involved. The other large producer of flux emeralds is Pierre Gilson Sr. , which has been on the market since 1964. Gilson's emeralds are usually grown on natural colorless beryl seeds which become coated on both sides. Growth occurs at the rate of 1 mm per month, a typical seven-month growth run producing emerald crystals of 7 mm of thickness (Nassau, K. Gems Made By Man, 1980).

Hydrothermal synthetic emeralds have been attributed to IG Farben, Nacken, Tairus, and others, but the first satisfactory commercial product was that of Johann Lechleitner of Innsbruck, Austria, which appeared on the market in the 1960s. Hydrothermal synthesis includes the various techniques of crystallizing substances from high-temperature Aqueous solutions at high Vapor pressures also termed "hydrothermal IG Farben (short for Interessen-Gemeinschaft Farbenindustrie AG, "syndicate of dyestuff corporations" and also called I Tairus ( Russian: Тайрус a Portmanteau of Тай ско ( Thai) and Рус ский ( Russian) is a synthetic Innsbruck is the capital city of the federal state of Tyrol in western Austria. Austria (Österreich ( officially the Republic of Austria (Republik Österreich These stones were initially sold under the names "Emerita" and "Symeralds", and they were grown as a thin layer of emerald on top of natural colorless beryl stones. Although not much is known about the original process, it is assumed that Leichleitner emeralds were grown in acid conditions. Later, from 1965 to 1970, the Linde Division of Union Carbide produced completely synthetic emeralds by hydrothermal synthesis. The Linde Group is the international Industrial gases and Engineering company founded in 1879 Union Carbide Corporation ( Union Carbide) is one of the oldest chemical and polymers companies in the United States, currently employing more than 3800 people According to their patents (US3,567,642 and US3,567,643), acidic conditions are essential to prevent the chromium (which is used as the colorant) from precipitating. Also, it is important that the silicon containing nutrient be kept away from the other ingredients in order to prevent nucleation and confine growth to the seed crystals. Growth occurs by a diffusion-reaction process, assisted by convection. Typical growth conditions include pressures of 700-1400 bars at temperatures of 500 to 600 °C with a temperature gradient of 10 to 25 °C. Growth rates as fast as 1/3 mm per day can be attained

Luminescence in ultraviolet light is considered a supplementary test when making a natural vs. Ultraviolet ( UV) light is Electromagnetic radiation with a Wavelength shorter than that of Visible light, but longer than X-rays synthetic determination, as many, but not all, natural emeralds are inert to ultraviolet light. Ultraviolet ( UV) light is Electromagnetic radiation with a Wavelength shorter than that of Visible light, but longer than X-rays Many synthetics are also UV inert. ^[9]

Synthetic emeralds are often referred to as "created", as their chemical and gemological composition is the same as their natural counterparts. The U.S. Federal Trade Commission (FTC) has very strict regulations as to what can and what cannot be called "synthetic" stone. The United States of America —commonly referred to as the The Federal Trade Commission ( FTC) is an independent agency of the United States government, established in 1914 by the Federal Trade Commission Act The FTC says: "§ 23. 23(c) It is unfair or deceptive to use the word "laboratory-grown," "laboratory-created," "[manufacturer name]-created," or "synthetic" with the name of any natural stone to describe any industry product unless such industry product has essentially the same optical, physical, and chemical properties as the stone named. "^[10]

Wispy veil-like inclusions are common in flux-grown synthetic emeralds.

Emerald in different cultures, and Emerald lore

The Gachala Emerald is one of the largest gem emeralds in the world at 858 carats (172 g). The Gachala Emerald is an uncut 5- cm Emerald crystal weighing 858 carats (172 g The carat is a unit of Mass used for measuring gems and Pearls Currently a carat is defined as exactly 200  mg (0 This stone was found in 1967 at La Vega de San Juan mine in Gachalá, Colombia. It is housed at the National Museum of Natural History of the Smithsonian Institution in Washington DC. The National Museum of Natural History is a Natural history Museum administered by the Smithsonian Institution, located on the National The Smithsonian Institution (smɪθsoʊnɪən is an educational and research institute and associated Museum complex administered and funded by the Government of

Emerald is regarded as the traditional birthstone for May, as well as the traditional gemstone for the astrological signs of Taurus , Cancer and sometimes Gemini. Early civilizations such as India and Babylon have attributed gemstones with magical properties Astrological signs represent twelve equal segments or divisions of the Zodiac. Taurus is the second Astrological sign in the Zodiac, originating from the constellation of Taurus. Cancer is the fourth Astrological sign in the Zodiac, originating from the constellation of Cancer. Gemini is the third Astrological sign in the Zodiac, originating from the constellation of Gemini. One of the more quaint anecdotes on emeralds was by the 16th century historian Brantome, who referred to the many impressive emeralds the Spanish under Cortez had brought back to Europe from Latin America. On one of Cortez most famous emeralds he had the text engraved Inter Natos Mulierum non sur-rexit mayor (Among them borne of woman there hath not arisen a greater Man. XI, 11) which referred to John the Baptist. Saint John the Baptist ( heb. Jochanan ben Sacharja, arab. يحيى Yaḥyā or يوحنا Yūḥanna, aram. Brantome considered engraving such a beautiful and simple product of nature sacrilegious and considered this act the cause for Cortez loss of an extremely precious pearl (to which he dedicated a work A beautiful and incomparable pearl) and even for the death of King Charles IX who died soon after. Charles IX may refer to Charles IX of France (1550–1574 Charles IX of Sweden (1550–1611 ^[11]

High Priest Breastplate

In Exodus chapters 28 and 39, a number of precious stones are mentioned to be placed in the High Priest's Breastplate, representing the different tribes of Israel. Exodus ( Greek: έξοδος eksodos = "departure" is the second book of the Jewish Torah and of the Christian Old Testament. This is generally considered to be (one of) the origin(s) of our present day tradition of birthstones. Birthday is the name given to the date of the anniversary of a person's birth

According to Rebbenu Bachya, and the King James Version, the Hebrew word Nofech in Exodus 28:18 means Emerald, and was the stone on the Hoshen representing the tribe of Judah. Bahye ben Asher ( Hebrew: בחיי בן אשר) or Bahye ben Asher ben Halawa also known as the Rabbeinu Behaye, born about the middle of the Exodus ( Greek: έξοδος eksodos = "departure" is the second book of the Jewish Torah and of the Christian Old Testament. Hoshen / Choshen is a Hebrew word usually translated as breastplate; in English language contexts it refers to a specific Breastplate The Tribe of Judah ( was one of the Tribes of Israel. At its height it was the leading tribe of the Kingdom of Judah, and occupied most of the territory of the kingdom However, the Septuagint translates the word as Anthrax, meaning coal, probably in reference to the colour of burning coal, and therefore many rabbinical sources, and most scholars, consider Nofech to mean a red garnet – traditionally called a carbuncle, which happens to be the Vulgate's translation of the word. The Septuagint (ˈsɛptuədʒɪnt or simply " LXX " is the Koine Greek version of the Hebrew Bible, translated in stages between the The garnet group includes a group of minerals that have been used since the Bronze Age as gemstones and abrasives A carbuncle is an archaic name given to any red Cabachon cut Gemstone. The Vulgate is an early Fifth Century version of the Bible in Latin, and largely the result of the labours of Jerome, who was commissioned by ^[12] There is a wide range of views among traditional sources about which tribe the stone refers to. ^[13]

There are many complexities to identifying the Emerald as being the third stone or perhaps another stone on the breast plate. Multiple translations of the bible^[13] have created confusion about the nomenclature of the different stones. Another important fact is that in actuality there are two different breastplates made within a period of 800 years, and where it is assumed the first breastplate did not carry an Emerald but a green Felspar, and a real Emerald in the second breastplate. Feldspar is the name of a group of rock-forming Minerals which make up as much as 60% of the Earth 's crust. ^[13] Finally the 12th stone in the Breastplate (which in the original text was actually listed as the 6th stone)^[13] has more generally been identified as Beryl which was already included in the group of stones generally referred to as Smaragdus by Theophrastus in the Greek era. Theophrastus ( Greek:; 371 – c 287 BC a Greek native of Eressos in Lesbos, was the successor of Aristotle in the Peripatetic ^[14] Further unreferenced claims regarding the possibility of what gemstone the Emerald could really have been include Jasper, and even Rubies. A Ruby is a pink to blood-red Gemstone, a variety of the Mineral Corundum ( Aluminium oxide)

In some cultures, the emerald is the traditional gift for the 55th wedding anniversary. A wedding anniversary is the Anniversary of the date on which a Wedding took place It is also used as a 20th and 35th wedding anniversary stone.

Famous emeralds