The franc is the currency and legal tender of Switzerland and Liechtenstein. The Swiss National Bank issues banknotes and the federal mint Swissmint issues coins; the smaller denomination, a hundredth of a franc, is a Rappen in German, centime in French, centesimo in Italian, rap in Romansh. The ISO code of the currency used by banks and financial institutions is CHF, although Fr. is widely used by businesses and advertisers. The Latinate "CH" stands for Confoederatio Helvetica. Given the different languages used in Switzerland, Latin is used for language-neutral inscriptions on its coins. Before 1798, about 75 entities were making coins in Switzerland, including the 25 cantons and half-cantons, 16 cities, abbeys, resulting in about 860 different coins in circulation, with different values and monetary systems; the local Swiss currencies included the Basel thaler, Berne thaler, Fribourg gulden, Geneva thaler, Geneva genevoise, Luzern gulden, Neuchâtel gulden, St. Gallen thaler, Schwyz gulden, Solothurn thaler, Valais thaler, Zürich thaler.
In 1798, the Helvetic Republic introduced the franc, a currency based on the Berne thaler, subdivided into 10 batzen or 100 centimes. The Swiss franc was equal to 6 3⁄4 grams of 1 1⁄2 French francs; this franc was issued until the end of the Helvetic Republic in 1803, but served as the model for the currencies of several cantons in the Mediation period. These 19 cantonal currencies were the Appenzell frank, Argovia frank, Basel frank, Berne frank, Fribourg frank, Geneva franc, Glarus frank, Graubünden frank, Luzern frank, St. Gallen frank, Schaffhausen frank, Schwyz frank, Solothurn frank, Thurgau frank, Ticino franco, Unterwalden frank, Uri frank, Vaud franc, Zürich frank. After 1815, the restored Swiss Confederacy attempted to simplify the system of currencies once again; as of 1820, a total of 8,000 distinct coins were current in Switzerland: those issued by cantons, cities and principalities or lordships, mixed with surviving coins of the Helvetic Republic and the pre-1798 Helvetic Republic.
In 1825, the cantons of Berne, Fribourg, Solothurn and Vaud formed a monetary concordate, issuing standardised coins, the so-called Konkordanzbatzen, still carrying the coat of arms of the issuing canton, but interchangeable and identical in value. The reverse side of the coin displayed a Swiss cross with the letter C in the center. Although 22 cantons and half-cantons issued coins between 1803 and 1850, less than 15% of the money in circulation in Switzerland in 1850 was locally produced, with the rest being foreign brought back by mercenaries. In addition, some private banks started issuing the first banknotes, so that in total, at least 8000 different coins and notes were in circulation at that time, making the monetary system complicated. To solve this problem, the new Swiss Federal Constitution of 1848 specified that the federal government would be the only entity allowed to issue money in Switzerland; this was followed two years by the first Federal Coinage Act, passed by the Federal Assembly on 7 May 1850, which introduced the franc as the monetary unit of Switzerland.
The franc was introduced at par with the French franc. It replaced the different currencies of the Swiss cantons, some of, using a franc, worth 1.5 French francs. In 1865, Belgium and Switzerland formed the Latin Monetary Union, in which they agreed to value their national currencies to a standard of 4.5 grams of silver or 0.290322 grams of gold. After the monetary union faded away in the 1920s and ended in 1927, the Swiss franc remained on that standard until 1936, when it suffered its sole devaluation, on 27 September during the Great Depression; the currency was devalued by 30% following the devaluations of the British pound, U. S. dollar and French franc. In 1945, Switzerland joined the Bretton Woods system and pegged the franc to the US dollar at a rate of $1 = 4.30521 francs. This was changed to $1 = 4.375 francs in 1949. The Swiss franc has been considered a safe-haven currency, with a legal requirement that a minimum of 40% be backed by gold reserves. However, this link to gold, which dated from the 1920s, was terminated on 1 May 2000 following a referendum.
By March 2005, following a gold-selling program, the Swiss National Bank held 1,290 tonnes of gold in reserves, which equated to 20% of its assets. In November 2014, the referendum on the "Swiss Gold Initiative" which proposed a restoration of 20% gold backing for the Swiss franc, was voted down. In March 2011, the franc climbed past the US$1.10 mark. In June 2011, the franc climbed past US$1.20 as investors sought safety as the Greek sovereign debt crisis continued. Continuation of the same crisis in Europe and the debt crisis in the US propelled the Swiss franc past US$1.30 as of August 2011, prompting the Swiss National Bank to boost the franc's liquidity to try to counter its "massive overvaluation". The Economist argued that its Big Mac Index in July 2011 indicated an overvaluation of 98% over the dollar, cited Swiss companies releasing profit warnings and threatening to move operations out of the country due to the strength of the franc. Demand for francs and franc-denominated assets was so strong that nominal short-term Swiss interest rates became negative.
On 6 September 2011, when the ex
Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. At room temperature and pressure, another solid form of carbon known as graphite is the chemically stable form, but diamond never converts to it. Diamond has the highest hardness and thermal conductivity of any natural material, properties that are utilized in major industrial applications such as cutting and polishing tools, they are the reason that diamond anvil cells can subject materials to pressures found deep in the Earth. Because the arrangement of atoms in diamond is rigid, few types of impurity can contaminate it. Small numbers of defects or impurities color diamond blue, brown, purple, orange or red. Diamond has high optical dispersion. Most natural diamonds have ages between 1 billion and 3.5 billion years. Most were formed at depths between 150 and 250 kilometers in the Earth's mantle, although a few have come from as deep as 800 kilometers. Under high pressure and temperature, carbon-containing fluids dissolved minerals and replaced them with diamonds.
Much more they were carried to the surface in volcanic eruptions and deposited in igneous rocks known as kimberlites and lamproites. Synthetic diamonds can be grown from high-purity carbon under high pressures and temperatures or from hydrocarbon gas by chemical vapor deposition. Imitation diamonds can be made out of materials such as cubic zirconia and silicon carbide. Natural and imitation diamonds are most distinguished using optical techniques or thermal conductivity measurements. Diamond is a solid form of pure carbon with its atoms arranged in a crystal. Solid carbon comes in different forms known as allotropes depending on the type of chemical bond; the two most common allotropes of pure carbon are graphite. In graphite the bonds are sp2 orbital hybrids and the atoms form in planes with each bound to three nearest neighbors 120 degrees apart. In diamond they are sp3 and the atoms form tetrahedra with each bound to four nearest neighbors. Tetrahedra are rigid, the bonds are strong, of all known substances diamond has the greatest number of atoms per unit volume, why it is both the hardest and the least compressible.
It has a high density, ranging from 3150 to 3530 kilograms per cubic metre in natural diamonds and 3520 kg/m³ in pure diamond. In graphite, the bonds between nearest neighbors are stronger but the bonds between planes are weak, so the planes can slip past each other. Thus, graphite is much softer than diamond. However, the stronger bonds make graphite less flammable. Diamonds have been adapted for many uses because of the material's exceptional physical characteristics. Most notable are its extreme hardness and thermal conductivity, as well as wide bandgap and high optical dispersion. Diamond's ignition point is 720 -- 800 °C in 850 -- 1000 °C in air; the equilibrium pressure and temperature conditions for a transition between graphite and diamond is well established theoretically and experimentally. The pressure changes linearly between 1.7 GPa at 0 K and 12 GPa at 5000 K. However, the phases have a wide region about this line where they can coexist. At normal temperature and pressure, 20 °C and 1 standard atmosphere, the stable phase of carbon is graphite, but diamond is metastable and its rate of conversion to graphite is negligible.
However, at temperatures above about 4500 K, diamond converts to graphite. Rapid conversion of graphite to diamond requires pressures well above the equilibrium line: at 2000 K, a pressure of 35 GPa is needed. Above the triple point, the melting point of diamond increases with increasing pressure. At high pressures and germanium have a BC8 body-centered cubic crystal structure, a similar structure is predicted for carbon at high pressures. At 0 K, the transition is predicted to occur at 1100 GPa; the most common crystal structure of diamond is called diamond cubic. It is formed of unit cells stacked together. Although there are 18 atoms in the figure, each corner atom is shared by eight unit cells and each atom in the center of a face is shared by two, so there are a total of eight atoms per unit cell; each side of the unit cell is 3.57 angstroms in length. A diamond cubic lattice can be thought of as two interpenetrating face-centered cubic lattices with one displaced by 1/4 of the diagonal along a cubic cell, or as one lattice with two atoms associated with each lattice point.
Looked at from a <1 1 1> crystallographic direction, it is formed of layers stacked in a repeating ABCABC... pattern. Diamonds can form an ABAB... structure, known as hexagonal diamond or lonsdaleite, but this is far less common and is formed under different conditions from cubic carbon. Diamonds occur most as euhedral or rounded octahedra and twinned octahedra known as macles; as diamond's crystal structure has a cubic arrangement of the atoms, they have many facets that belong to a cube, rhombicosidodecahedron, tetrakis hexahedron or disdyakis dodecahedron. The crystals can be elongated. Diamonds are found coated in nyf, an opaque gum-like skin; some diamonds have opaque fibers. They are referred to as opaque if the fibers
Christie's is a British auction house. It was founded in 1766 by James Christie, its main premises are on King Street, St James's, in London and in the Rockefeller Center in New York City. The company is owned by the holding company of François-Henri Pinault. Sales in 2015 totalled £4.8 billion. In 2017 the Salvator Mundi was sold for $450.3 million at Christie's, which at that time was the highest price paid for a single painting at an auction. The official company literature states that founder James Christie conducted the first sale in London, England, on 5 December 1766, the earliest auction catalogue the company retains is from December 1766. However, other sources note that James Christie rented auction rooms from 1762, newspaper advertisements for Christie's sales dating from 1759 have been traced. Christie's was a public company, listed on the London Stock Exchange, from 1973 to 1999. In 1974, Jo Floyd was appointed chairman of Christie's, he served as chairman of Christie's International plc from 1976 to 1988, until handing over to Lord Carrington, was a non-executive director until 1992.
Christie's International Inc. held its first sale in the United States in 1977. Christie's growth was steady since 1989, when it had 42 % of the auction market. In 1990, the company reversed a long-standing policy and guaranteed a minimum price for a collection of artworks in its May auctions. In 1996, sales exceeded those of Sotheby's for the first time since 1954. However, profits did not grow at the same pace. In 1993, Christie's paid $12.7 million for the London gallery Spink & Son, which specialised in Oriental art and British paintings. The company bought Leger Gallery for $3.3 million in 1996, merged it with Spink to become Spink-Leger. Spink-Leger closed in 2002. To make itself competitive with Sotheby's in the property market, Christie's bought Great Estates in 1995 the largest network of independent estate agents in North America, changing its name to Christie's Great Estates Inc. In December 1997, under the chairmanship of Lord Hindlip, Christie's put itself on the auction block, but after two months of negotiations with the consortium-led investment firm SBC Warburg Dillon Read it did not attract a bid high enough to accept.
In May 1998, François Pinault's holding company, Groupe Artémis S. A. first bought 29.1 percent of the company for $243.2 million, subsequently purchased the rest of it in a deal that valued the entire company at $1.2 billion. The company has since not been reporting profits, its policy, in line with UK accounting standards, is to convert non-UK results using an average exchange rate weighted daily by sales throughout the year. In 2002, Christie's France held its first auction in Paris. Like Sotheby's, Christie's became involved in high-profile private transactions. In 2006, Christie's offered a reported $21 million guarantee to the Donald Judd Foundation and displayed the artist's works for five weeks in an exhibition that won an AICA award for "Best Installation in an Alternative Space". In 2007 it brokered a $68 million deal that transferred Thomas Eakins's The Gross Clinic from the Jefferson Medical College at the Thomas Jefferson University in Philadelphia to joint ownership by the Philadelphia Museum of Art and the Pennsylvania Academy of the Fine Arts.
In the same year, the Haunch of Venison gallery became a subsidiary of the company. On 28 December 2008, The Sunday Times reported that Pinault's debts left him "considering" the sale of Christie's and that a number of "private equity groups" were thought to be interested in its acquisition. In January 2009, the company employed 2,100 people worldwide, though an unspecified number of staff and consultants were soon to be cut due to a worldwide downturn in the art market. With sales for premier Impressionist and contemporary artworks tallying only US$248.8 million in comparison to US$739 million just a year before, a second round of job cuts began after May 2009. Guy Bennett resigned just before to the beginning of the summer 2009 sales season. Although the economic downturn has encouraged some collectors to sell art, others are unwilling to sell in a market which may yield only bargain prices. On 1 January 2017, Guillaume Cerutti was appointed chief executive officer. Patricia Barbizet was appointed chief executive officer of Christie's in 2014, the first female CEO of the company.
She replaced Steven Murphy, hired in 2010 to develop their online presence and launch in new markets, such as China. In 2012, Impressionist works, which dominated the market during the 1980s boom, were replaced by contemporary art as Christie's top category. Asian art was the third most-lucrative area. With income from classic auctioneering falling, treaty sales made £413.4 million in the first half of 2012, an increase of 53% on the same period last year. The company has promoted curated events, centred on a theme rather than an art classification or time period; as part of a companywide review in 2017, Christie's announced the layoffs of 250 employees, or 12 percent of the total work force, based in Britain and Europe. From 2008 until 2013, Christie's charged 25 percent for the first $50,000. From 2013, it charged 25 percent for the first $75,000. Christie's main London salesroom is on
A diamond cut is a style or design guide used when shaping a diamond for polishing such as the brilliant cut. Cut does not refer to shape, but the symmetry and polish of a diamond; the cut of a diamond affects a diamond's brilliance. In order to best use a diamond gemstone's material properties, a number of different diamond cuts have been developed. A diamond cut constitutes a more or less symmetrical arrangement of facets, which together modify the shape and appearance of a diamond crystal. Diamond cutters must consider several factors, such as the shape and size of the crystal, when choosing a cut; the practical history of diamond cuts can be traced back to the Middle Ages, while their theoretical basis was not developed until the turn of the 20th century. Design creation and innovation continue to the present day: new technology—notably laser cutting and computer-aided design—has enabled the development of cuts whose complexity, optical performance, waste reduction were hitherto unthinkable.
The most popular of diamond cuts is the modern round brilliant, whose facet arrangements and proportions have been perfected by both mathematical and empirical analysis. Popular are the fancy cuts, which come in a variety of shapes, many of which were derived from the round brilliant. A diamond's cut is evaluated by trained graders, with higher grades given to stones whose symmetry and proportions most match the particular "ideal" used as a benchmark; the strictest standards are applied to the round brilliant. Different countries base their cut grading on different ideals: one may speak of the American Standard or the Scandinavian Standard, to give but two examples; the history of diamond cuts can be traced to the late Middle Ages, before which time diamonds were employed in their natural octahedral state—anhedral diamonds were not used in jewelry. The first "improvements" on nature's design involved a simple polishing of the octahedral crystal faces to create and unblemished facets, or to fashion the desired octahedral shape out of an otherwise unappealing piece of rough.
This was called the point cut and dates from the mid 14th century. By the mid 15th century, the point cut began to be improved upon: a little less than one half of the octahedron would be sawn off, creating the table cut; the importance of a culet was realised, some table-cut stones may possess one. The addition of four corner facets created the old single cut. Neither of these early cuts would reveal. At the time, diamond was valued chiefly for its adamantine superlative hardness. For this reason, colored gemstones such as ruby and sapphire were far more popular in jewelry of the era. In or around 1476, Lodewyk van Berquem, a Flemish polisher of Bruges, introduced the technique of absolute symmetry in the disposition of facets using a device of his own invention, the scaif, he cut stones in the shape known as briolette. About the middle of the 16th century, the rose or rosette was introduced in Antwerp: it consisted of triangular facets arranged in a symmetrical radiating pattern, but with the bottom of the stone left flat—essentially a crown without a pavilion.
Many large, famous Indian diamonds of old feature a rose-like cut. However, Indian "rose cuts" were far less symmetrical as their cutters had the primary interest of conserving carat weight, due to the divine status of diamond in India. In either event, the rose cut continued to evolve, with its depth and arrangements of facets being tweaked; the first brilliant cuts were introduced in the middle of the 17th century. Known as Mazarins, they had 17 facets on the crown, they are called double-cut brilliants as they are seen as a step up from old single cuts. Vincent Peruzzi, a Venetian polisher increased the number of crown facets from 17 to 33, thereby increasing the fire and brilliance of the cut gem, properties that in the Mazarin were incomparably better than in the rose, yet Peruzzi-cut diamonds, when seen nowadays, seem exceedingly dull compared to modern-cut brilliants. Because the practice of bruting had not yet been developed, these early brilliants were all rounded squares or rectangles in cross-section.
Given the general name of cushion—what are known today as old mine cuts—these were common by the early 18th century. Sometime the old European cut was developed, which had a shallower pavilion, more rounded shape, different arrangement of facets; the old European cut was the forerunner of modern brilliants and was the most advanced in use during the 19th century. Around 1900, the development of diamond saws and good jewelry lathes enabled the development of modern diamond cutting and diamond cuts, chief among them the round brilliant cut. In 1919, Marcel Tolkowsky analyzed this cut: his calculations took both brilliance and fire into consideration, creating a delicate balance between the two. Tolkowsky's calculations would serve as the basis for all future brilliant cut modifications and standards. Tolkowsky's model of the "ideal" cut is not perfect; the original mo
A chemically pure and structurally perfect diamond is transparent with no hue, or color. However, in reality no gem-sized natural diamonds are perfect; the color of a diamond may be affected by chemical impurities and/or structural defects in the crystal lattice. Depending on the hue and intensity of a diamond's coloration, a diamond's color can either detract from or enhance its value. For example, most white diamonds are discounted in price when more yellow hue is detectable, while intense pink diamonds or blue diamonds can be more valuable. Of all colored diamonds, red diamonds are the rarest; the Aurora Pyramid of Hope displays a spectacular array of colored diamonds, including red diamonds. Diamonds occur in a variety of colors—steel gray, blue, orange, green, pink to purple and black. Colored diamonds contain interstitial impurities or structural defects that cause the coloration, pure diamonds are transparent and colorless. Diamonds are scientifically classed into two main types and several subtypes, according to the nature of impurities present and how these impurities affect light absorption: Type I diamonds have nitrogen atoms as the main impurity at a concentration of 0.1%.
If the nitrogen atoms are in pairs they do not affect the diamond's color. If the nitrogen atoms are in large even-numbered aggregates they impart a yellow to brown tint. About 98% of gem diamonds are type Ia, most of these are a mixture of IaA and IaB material: these diamonds belong to the Cape series, named after the diamond-rich region known as Cape Province in North Africa, whose deposits are Type Ia. If the nitrogen atoms are dispersed throughout the crystal in isolated sites, they give the stone an intense yellow or brown tint. Synthetic diamond containing nitrogen is Type Ib. Type I diamonds absorb from 320 nm, they have a characteristic fluorescence and visible absorption spectrum. Type II diamonds have no measurable nitrogen impurities. Type II diamonds absorb in a different region of the infrared, transmit in the ultraviolet below 225 nm, unlike Type I diamonds, they have differing fluorescence characteristics, but no discernible visible absorption spectrum. Type IIa diamond can be colored pink, red, or brown due to structural anomalies arising through plastic deformation during crystal growth—these diamonds are rare, but constitute a large percentage of Australian production.
Type IIb diamonds, which account for 0.1% of gem diamonds, are light blue due to scattered boron within the crystal matrix. However, a blue-grey color may occur in Type Ia diamonds and be unrelated to boron. Not restricted to type are green diamonds, whose color is caused by GR1 color centers in the crystal lattice produced by exposure to varying quantities of radiation. Pink and red are caused by plastic deformation of the crystal lattice from pressure. Black diamonds are caused by microscopic black or gray inclusions of other materials such as graphite or sulfides and/or microscopic fractures. Opaque or opalescent white diamonds are caused by microscopic inclusions. Purple diamonds are caused by a combination of high hydrogen content; the majority of diamonds that are mined are in a range of pale yellow or brown color, termed the normal color range. Diamonds that are of intense yellow or brown, or any other color are called fancy color diamonds. Diamonds that are of the highest purity are colorless, appear a bright white.
The degree to which diamonds exhibit body color is one of the four value factors by which diamonds are assessed. Diamonds have a color grading system; this system goes from D to Z. The more colorless a diamond is, the rarer and more valuable it is because it appears white and brighter to the eye. Color grading of diamonds was performed as a step of sorting rough diamonds for sale by the London Diamond Syndicate; as the diamond trade developed, early diamond grades were introduced by various parties in the diamond trade. Without any co-operative development these early grading systems lacked standard nomenclature, consistency; some early grading scales were. Numerous terms developed to describe diamonds of particular colors: golconda, jagers, blue white, fine white, gem blue, etc. Refers to a grading scale for diamonds in the normal color range used by internationally recognized laboratories; the scale ranges from D, colorless to Z, a pale yellow or brown color. Brown diamonds darker than K color are described using their letter grade, a descriptive phrase, for example M Faint Brown.
Diamonds with more depth of color than Z color fall into the fancy color diamond range. Diamond color is graded by comparing a sample stone to a master stone set of diamonds; each master stone is known to exhibit the least amount of body color that a diamond in that color grade may exhibit. A trained diamond grader compares a diamond of unknown grade against the series of master stones, assessing where in the range of color the diamond resides; this process occurs in a lighting box, fitted with daylight equivalent lamps. Accurate color grading can only be performed with diamond unset, as the comparison with master