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Other liquids, including synthetic oils and polymers with refractive indexes close to that of emeralds, such as "Opticon", are also used.
These treatments are typically applied in a vacuum chamber under mild heat, to open the pores of the stone and allow the fracture-filling agent to be absorbed more effectively.
The U.S. Federal Trade Commission requires the disclosure of this treatment when an oil treated emerald is sold.
The use of oil is traditional and largely accepted by the gem trade, although oil treated emeralds are worth much less than un-treated emeralds of similar quality.
Other treatments, for example the use of green-tinted oil, are not acceptable in the trade.
Gems are graded on a four-step scale; "none", "minor", "moderate" and "highly" enhanced.
These categories reflect levels of enhancement, not "clarity".
A gem graded "none" on the enhancement scale may still exhibit visible inclusions.
Laboratories apply these criteria differently.
Some gemologists consider the mere presence of oil or polymers to constitute enhancement.
Others may ignore traces of oil if the presence of the material does not improve the look of the gemstone.
========,2,Emerald mines.
Emeralds in antiquity have been mined in Egypt since 1500 BCE, and India, and Austria since at least the 14th century CE.
Colombia is by far the world's largest 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, Coscuez, and Chivor.
Rare "trapiche" emeralds are found in Colombia, distinguished by ray-like spokes of dark impurities.
Zambia is the world's second biggest producer, with its Kafubu River area deposits (Kagem Mines) about southwest of Kitwe responsible for 20% of the world's production of gem quality stones in 2004.
In the first half of 2011 the Kagem mines produced 3.74 tons of emeralds.
Emeralds are found all over the world in countries such as Afghanistan, Australia, Austria, Brazil, Bulgaria, Cambodia, Canada, China, Egypt, Ethiopia, France, Germany, India, Italy, Kazakhstan, Madagascar, Mozambique, Namibia, Nigeria, Norway, Pakistan, Russia, Somalia, South Africa, Spain, Switzerland, Tanzania, the United States, Zambia, and Zimbabwe.
In the US, emeralds have been found in Connecticut, Montana, Nevada, North Carolina, and South Carolina.
In Canada, in 1997 emeralds were discovered in the Yukon.
========,3,Origin determinations.
Since the onset of concerns regarding diamond origins, research has been conducted to determine if the mining location could be determined for an emerald already in circulation.
Traditional research used qualitative guidelines such as an emerald’s color, style and quality of cutting, type of fracture filling, and/or the anthropological origins of the artifacts bearing the mineral to determine the emerald's mine location.
More recent studies using energy dispersive X-ray spectroscopy methods have uncovered trace chemical element differences between emeralds; even emeralds mined within close proximity to one another.
American gemologist David Cronin and his colleagues have extensively examined the chemical signatures of emeralds resulting from fluid dynamics and subtle precipitation mechanisms, and their research demonstrated the chemical homogeneity of emeralds from the same mining location and the statistical differences that exist between emeralds from different mining locations, including those between the three locations: Muzo, Coscuez, and Chivor, in Colombia, South America.
========,2,Synthetic emerald.
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, likely involving a lithium vanadate flux process, as Chatham's emeralds do not have any water and contain traces of vanadate, molybdenum and vanadium.
The other large producer of flux emeralds was Pierre Gilson Sr., whose products have been on the market since 1964.
Gilson's emeralds are usually grown on natural colorless beryl seeds, which are 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.
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.
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.
Later, from 1965 to 1970, the Linde Division of Union Carbide produced completely synthetic emeralds by hydrothermal synthesis.
According to their patents (attributable to E.M. Flanigen), 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 to prevent nucleation and confine growth to the seed crystals.
Growth occurs by a diffusion-reaction process, assisted by convection.
The largest producer of hydrothermal emeralds today is Tairus in Russia, which has succeeded in synthesizing emeralds with chemical composition similar to emeralds in alkaline deposits in Colombia, and whose products are thus known as “Colombian Created Emeralds” or “Tairus Created Emeralds”.
Luminescence in ultraviolet light is considered a supplementary test when making a natural vs. synthetic determination, as many, but not all, natural emeralds are inert to ultraviolet light.
Many synthetics are also UV inert.
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 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."
========,2,Emerald in different cultures, and emerald lore.
Emerald is regarded as the traditional birthstone for May as well as the traditional gemstone for the astrological signs of Cancer.
One of the quainter anecdotes about emeralds was told by the 16th-century historian Brantôme, who referred to the many impressive emeralds the Spanish under Cortez had brought back to Europe from Latin America.
On one of Cortez's most notable emeralds he had the text engraved, "Inter Natos Mulierum non sur-rexit mayor" ("Among those born of woman there hath not arisen a greater," Matthew 11:11) which referred to John the Baptist.
Brantôme considered engraving such a beautiful and simple product of nature sacrilegious and considered this act the cause for Cortez's 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 of France, who died soon afterward.
The chief deity of one of India's most famous temple, the Meenakshi Amman Temple in Madurai, is the goddess Meenakshi, whose idol is traditionally thought to be made of emerald.
========,1,preface.
An episcopal polity is a hierarchical form of church governance ("ecclesiastical polity") in which the chief local authorities are called bishops.
(The word "bishop" derives, via the British Latin and Vulgar Latin term "*ebiscopus"/"*biscopus", from the Ancient Greek "epískopos" meaning "overseer".)
It is the structure used by many of the major Christian Churches and denominations, such as the Roman Catholic, Eastern Orthodox, Oriental Orthodox, Church of the East, Anglican and Lutheran churches or denominations, and other churches founded independently from these lineages.
Churches with an episcopal polity are governed by bishops, practicing their authorities in the dioceses and conferences or synods.
Their leadership is both sacramental and constitutional; as well as performing ordinations, confirmations, and consecrations, the bishop supervises the clergy within a local jurisdiction and is the representative both to secular structures and within the hierarchy of the church.
Bishops are considered to derive their authority from an unbroken, personal apostolic succession from the Twelve Apostles of Jesus.
Bishops with such authority are said to represent the historical episcopate or historic episcopate.
Churches with this type of government usually believe that the Church requires episcopal government as described in the New Testament (see 1 Timothy 3 and 2 Timothy 1).
In some systems, bishops may be subject to bishops holding a higher office (variously called archbishops, metropolitans, and/or patriarchs, depending upon the tradition).
They also meet in councils or synods.
These gatherings, subject to presidency by higher ranking bishops, usually make important decisions, though the synod or council may also be purely advisory.
For much of the written history of institutional Christianity, episcopal government was the only known form of church organization.
This changed at the Reformation.
Many Protestant churches are now organized by either congregational or presbyterian church polities, both descended from the writings of John Calvin, a Protestant reformer working and writing independently following the break with the Roman Catholic Church precipitated by The Ninety-Five Theses of Martin Luther.
========,2,Overview of episcopal churches.
The definition of the word "episcopal" has variation among Christian traditions.
There are subtle differences in governmental principles among episcopal churches at the present time.
To some extent the separation of episcopal churches can be traced to these differences in ecclesiology, that is, their theological understanding of church and church governance.
For some, "episcopal churches" are churches that use a hierarchy of bishops that regard themselves as being in an unbroken, personal apostolic succession.
Episcopal is also commonly used to distinguish between the various organizational structures of denominations.
For instance, the word "presbyterian" (, presbítes) is used to describe a church governed by a hierarchy of assemblies of elected elders, referred to as Presbyterian.
Similarly, "episcopal" is used to describe a church governed by bishops.
Self-governed local congregations, governed neither by elders nor bishops, are usually referred to as "Congregational".
More specifically, the title "Episcopal" (capitalized in this instance) is applied to several churches historically based within Anglicanism ("Episcopalianism") including those still in communion with the Church of England.
Using these definitions, examples of specific episcopal churches include:
***LIST***.
Some Lutheran churches practice congregational polity or a form of presbyterian polity.
Others, including the Church of Sweden, practice episcopal polity; the Church of Sweden also counts its bishops among the historic episcopate as do some American Lutheran churches like the Anglo-Lutheran Catholic Church, Lutheran Orthodox Church, Lutheran Church-International, and the Lutheran Episcopal Communion.
Many Methodist churches (see The United Methodist Church, among others) retain the form and function of episcopal polity, although in a modified form, called connexionalism.
Since all trace their ordinations to an Anglican priest, John Wesley, it is generally considered that their bishops do not share in apostolic succession, though United Methodists still affirm that their bishops share in the historic episcopate.
========,2,Before the Great Schism.
All orthodox Christians were in churches with an episcopal government, that is, one Church under local bishops and regional Patriarchs.
Writing between ca.
85 and 110, St. Ignatius of Antioch, Patriarch of Antioch, was the earliest of the Church fathers to define the importance of episcopal government.
Assuming Ignatius' view was the Apostolic teaching and practice, the line of succession was unbroken and passed through the four ancient Patriarchal sees (those local churches known to be founded by apostles), Rome, Jerusalem, Antioch and Alexandria.
Rome was the leading Patriarchate of the ancient four by virtue of its founding by Saints Peter and Paul and their martyrdom there, not to mention being the political center of the Roman empire at the time.
Some organizations (e.g.
the Assyrian Church of the East), though aloof from the political wranglings of imperial Christianity, nevertheless also practiced episcopal polity.
Shortly after the Roman Emperor Constantine I legalized Christianity in 321, he also constructed an elaborate second capital of the Roman Empire located at Byzantium and renamed it Constantinople, in 324.
The single Roman Empire was divided between these two autonomous administrative centers, Roman and Constantinopolitan, West and East, Latin speaking and Greek speaking.
This remained the status quo through the fourth century.
A deep chasm developed between the East and West, becoming critical around 350, known as the Aryan, or Nicene controversy.
The Eastern Christian Churches were thought by Constantine to believe against the Trinity; that Christ was lesser than God.
Hilary, Bishop of Poitiers, France, believed that the Eastern Church should be given the opportunity to, at least, be educated on the subject.
Constantine, in his wisdom, and upset by disagreement, banished Hilary to the East.
Hilary perfected his Greek language skills while in exile, and determined the great divide between Rome and the East was actually not a disagreement at all, and was merely a linguistic ignorance on the part of his Latin speaking contemporaries.
This truth became known in the West, though some differences lingered.
Hilary of Poitiers later became St. Hilary, Doctor of the Church, for exposing the true Christian beliefs of the Eastern Church.