Instruct: Given a question, retrieve relevant documents that answer the question.
Query: What types of diamonds are there?
Diamond type is a method of scientifically classifying diamonds by the level and type of their chemical impurities. Diamonds are separated into four types: Type Ia, Type Ib, Type IIa, and Type IIb. The impurities measured are at the atomic level within the crystal lattice of carbon atoms and so, unlike inclusions, require an infrared spectrometer to detect.
The Tereshchenko Diamond, sometimes known as the Tereshchenko Blue, is a 42.92 carat diamond of blue colour that is cut in the pear shape. The diamond is rare, belonging to the Type IIb diamond, and believed to originate from India. The Tereshchenko diamond is the second biggest blue diamond in the world. Shaped by Cartier for a private order by the Tereshchenko family, the diamond is in the rare Type IIb diamond.
The Marange diamond fields are an area of widespread small-scale diamond production in Chiadzwa, Mutare West, Zimbabwe. 'Although estimates of the reserves contained in this area vary wildly, some have suggested that it could be home to one of the world's richest diamond deposits'. The hugely prolific fields are regarded by some experts as the world's biggest diamond (in carats, not by value) find in more than a century. Production from Marange is controversial due to ongoing legal wrangles and government crackdowns on illegal miners and allegations of forced labour. In terms of carats produced, the Marange field is the largest diamond producing project in the world, estimated to have produced 16.9 million carats in 2013, or 13% of global rough diamond supply. Marange is estimated to have produced 12.0 million carats in 2012, 8.7 million carats in 2011, and 8.2 million carats in 2010. While some diamond mines produce rough valued at over $1000 per carat, average production at Marange is estimated at under $50 per carat.
The Cullinan mine continues to produce large stones. The Cullinan Heritage, a white diamond, was discovered in September 2009. This stone was the 19th biggest uncut diamond ever found and was sold in February 2010 to Chow Tai Fook Jewellery for $35.5m, the highest price ever paid for an uncut diamond. The previous record was held by Gem Diamonds' Leseli La Letšeng, which was bought for $18.4m by Graff Diamonds in December 2008.
The Cullinan Diamond is the largest gem-quality rough diamond ever found, weighing , discovered at the Premier No. 2 mine in Cullinan, South Africa, on 26 January 1905. It was named after Thomas Cullinan, the mine's chairman.
In August 2010 Zimbabwe resumed the sale of diamonds from the Marange fields. On August 11, buyers flew into the country's capital, Harare, from all over the world, including Israel, India, Lebanon and Russia to capitalise on the sale of over US$1.5 billion worth of diamonds. Press Reports describe the Marange find as, 'the biggest in southern Africa since diamonds were discovered in South Africa a century ago'.
Jewellery (British English) or jewelry (American English) consists of small decorative items worn for personal adornment, such as brooches, rings, necklaces, earrings, pendants, bracelets, and cufflinks. Jewellery may be attached to the body or the clothes. From a western perspective, the term is restricted to durable ornaments, excluding flowers for example. For many centuries metal, often combined with gemstones, has been the normal material for jewellery, but other materials such as shells and other plant materials may be used. It is one of the oldest type of archaeological artefact – with 100,000-year-old beads made from "Nassarius" shells thought to be the oldest known jewellery. The basic forms of jewellery vary between cultures but are often extremely long-lived; in European cultures the most common forms of jewellery listed above have persisted since ancient times, while other forms such as adornments for the nose or ankle, important in other cultures, are much less common.
The Winston Blue is the name given to what was the largest flawless vivid blue diamond bought by Harry Winston, Inc. (a wholly owned subsidiary of The Swatch Group from January 2013) on May 15, 2014, from an anonymous person for $23.8 million at Christie's Geneva Magnificent Jewels sale. The approximately $1.8003 million per carat price paid for the 13.22-carat diamond is a world record for a blue diamond. Harry Winston, Inc. had also bought a 101.73-carat colorless diamond named Winston Legacy at Christie's Geneva jewelry auction in 2013. The American luxury jeweler had then paid $26.7 million for the colorless diamond ($254,400 per carat), which is a world record for the highest price paid per carat for a colorless diamond.
The Cullinan diamond was found below the surface at Premier Mine in Cullinan, Transvaal Colony, by Frederick Wells, surface manager at the mine, on 26 January 1905. It was approximately long, wide, deep, and weighed . Newspapers called it the "Cullinan Diamond", a reference to Sir Thomas Cullinan, who opened the mine in 1902. It was three times the size of the Excelsior Diamond, found in 1893 at Jagersfontein Mine, weighing . Four of its eight surfaces were smooth, indicating that it once had been part of a much larger stone broken up by natural forces. It had a blue-white hue and contained a small pocket of air, which at certain angles produced a rainbow, or Newton's rings.
A great deal of emphasis is placed on the Canadian diamond industry as a welcome alternative to the blood or conflict diamonds mined in Africa. Canada was one of the main supporters of the Kimberly process, a certification initiative created in 2000 to help deter the trade of conflict diamonds. All diamonds mined and cut in the Northwest Territories of Canada are laser inscribed with a unique identification number so that retailers can assure they are conflict-free stones. 
Taking another oppositional cue from Africa and the disastrous impacts their mining programs had on the surrounding ecosystems, all Canadian diamond mines are overseen by the Canada Mining Regulations for the Northwest Territories. This program ensures the preservation of surrounding land and aquatic habitats.
There are four basic types of knitting needles (also called "knitting pins"). The first and most common type consists of two slender, straight sticks tapered to a point at one end, and with a knob at the other end to prevent stitches from slipping off. Such needles are usually 10-16 inches long but, due to the compressibility of knitted fabrics, may be used to knit pieces significantly wider. The most important property of needles is their diameter, which ranges from below 2 mm to 25 mm (roughly 1 inch). The diameter affects the size of stitches, which affects the gauge of the knitting and the elasticity of the fabric. Thus, a simple way to change gauge is to use different needles, which is the basis of uneven knitting. Although knitting needle diameter is often measured in millimeters, there are several different size systems, particularly those specific to the United States, the United Kingdom and Japan; a conversion table is given in the knitting needle article. Such knitting needles may be made out of any materials, but the most common materials are metals, wood, bamboo, and plastic. Different materials have different frictions and grip the yarn differently; slick needles such as metallic needles are useful for swift knitting, whereas rougher needles such as bamboo are less prone to dropping stitches. The knitting of new stitches occurs only at the tapered ends, and needles with lighted tips have been sold to allow knitters to knit in the dark.
"Hardness" is determined by comparison with other minerals. In the Mohs scale, a standard set of minerals are numbered in order of increasing hardness from 1 (talc) to 10 (diamond). A harder mineral will scratch a softer, so an unknown mineral can be placed in this scale by which minerals it scratches and which scratch it. A few minerals such as calcite and kyanite have a hardness that depends significantly on direction. Hardness can also be measured on an absolute scale using a sclerometer; compared to the absolute scale, the Mohs scale is nonlinear.
The carat (ct) (not to be confused with the karat, sometimes spelled carat, a unit of purity of gold alloys), is a unit of mass equal to 200 mg (0.2 g; 0.007055 oz) and is used for measuring gemstones and pearls.
The current definition, sometimes known as the metric carat, was adopted in 1907 at the Fourth General Conference on Weights and Measures, and soon afterwards in many countries around the world. The carat is divisible into one hundred "points" of two milligrams each. Other subdivisions, and slightly different mass values, have been used in the past in different locations.
Platinum is a member of the platinum group of elements and group 10 of the periodic table of elements. It has six naturally occurring isotopes. It is one of the rarer elements in Earth's crust, with an average abundance of approximately 5 μg/kg. It occurs in some nickel and copper ores along with some native deposits, mostly in South Africa, which accounts for 80% of the world production. Because of its scarcity in Earth's crust, only a few hundred tonnes are produced annually, and given its important uses, it is highly valuable and is a major precious metal commodity.
There are three basic types of knitting needles (also called "knitting pins"). The first and most common type consists of two slender, straight sticks tapered to a point at one end, and with a knob at the other end to prevent stitches from slipping off. Such needles are usually long but, due to the compressibility of knitted fabrics, may be used to knit pieces significantly wider. The most important property of needles is their diameter, which ranges from below 2 to 25 mm (roughly 1 inch). The diameter affects the size of stitches, which affects the gauge/tension of the knitting and the elasticity of the fabric. Thus, a simple way to change gauge/tension is to use different needles, which is the basis of uneven knitting. Although the diameter of the knitting needle is often measured in millimeters, there are several measurement systems, particularly those specific to the United States, the United Kingdom and Japan; a conversion table is given at knitting needle. Such knitting needles may be made out of any materials, but the most common materials are metals, wood, bamboo, and plastic. Different materials have different frictions and grip the yarn differently; slick needles such as metallic needles are useful for swift knitting, whereas rougher needles such as bamboo offer more friction and are therefore less prone to dropping stitches. The knitting of new stitches occurs only at the tapered ends. Needles with lighted tips have been sold to allow knitters to knit in the dark.
The second type of knitting needles are straight, double-pointed knitting needles (also called "DPNs"). Double-pointed needles are tapered at both ends, which allows them to be knit from either end. DPNs are typically used for circular knitting, especially smaller tube-shaped pieces such as sleeves, collars, and socks; usually one needle is active while the others hold the remaining active stitches. DPNs are somewhat shorter (typically 7 inches) and are usually sold in sets of four or five.
Cable needles are a special case of DPNs, although they are usually not straight, but dimpled in the middle. Often, they have the form of a hook. When cabling a knitted piece, a hook is easier to grab and hold the yarn. Cable needles are typically very short (a few inches), and are used to hold stitches temporarily while others are being knitted. Cable patterns are made by permuting the order of stitches; although one or two stitches may be held by hand or knit out of order, cables of three or more generally require a cable needle.
A goldsmith might have a wide array of skills and knowledge at their disposal. Gold, being the most malleable metal of all, offers unique opportunities for the worker. In today's world a wide variety of other metals, especially platinum alloys, also may be used frequently. 24 karat is pure gold and historically, was known as fine gold.
In the United Kingdom, the medal, more properly known as "The Queen's Diamond Jubilee Medal", was designed by Timothy Noad, a calligrapher and illuminator. It depicts on the obverse the Ian Rank-Broadley effigy of the Queen crowned with a tiara and is circumscribed by the inscription "ELIZABETH II DEI GRATIA REGINA FID DEF" (Latin for "Elizabeth II by the Grace of God, Queen, Defender of the Faith"). The reverse shows a faceted hexagon with a crowned royal cipher, inscribed with the years 1952 and 2012.
Eight Commonwealth realms in the Caribbean—Antigua and Barbuda, The Bahamas, Barbados, Grenada, Jamaica, Saint Kitts and Nevis, Saint Lucia, and Saint Vincent and the Grenadines—have each issued a Diamond Jubilee medal. The obverse bears the same effigy of the Queen as does the British medal circumscribed by the words "DIAMOND JUBILEE HM QUEEN ELIZABETH II". The reverse shows the royal cypher of Elizabeth II with "CARIBBEAN REALMS" above and the years "1952–2012" below. The medal itself is rhodium plated.
Many of the conflicting versions about the origin of the "Spoonmaker's Diamond", a major treasure of the Topkapi Palace in Istanbul, link it with Ali Pasha – though their historical authenticity is doubtful.
There is varying and sometimes inconsistent nomenclature differentiating substances, which include truly non-stoichiometric examples, from chemical compounds, which require the fixed ratios. Many solid chemical substances—for example many silicate minerals—are chemical substances, but do not have simple formulae reflecting chemically bonding of elements to one another in fixed ratios; even so, these crystalline substances are often called "non-stoichiometric compounds". It may be argued that they are related to, rather than being chemical compounds, insofar as the variability in their compositions is often due to either the presence of foreign elements trapped within the crystal structure of an otherwise known true "chemical compound", or due to perturbations in structure relative to the known compound that arise because of an excess of deficit of the constituent elements at places in its structure; such non-stoichiometric substances form most of the crust and mantle of the Earth. Other compounds regarded as chemically identical may have varying amounts of heavy or light isotopes of the constituent elements, which changes the ratio of elements by mass slightly.
Sam Carter (Nigel Patrick) is a jeweller's clerk who dreams of stealing a fortune in diamonds and eventually does so but kills a man in the process. He then embarks on the highlife but is pursued across Europe by Milo March (Jack Palance) a private detective who suspects that not all is above board. However, Milo is not alone in his pursuit as Trudi Hall (Anita Ekberg) has her own ideas as to how the money would be best spent. Also two thugs, Martin Lomer (Bonar Colleano) and Gerard Heinz (Robert Stone) are after the Largest Diamond in the stolen hoard. All of the main characters end up fighting and trying to outwit each other over the Largest Diamond worth $700,00 on a Train going to London. This Precious Diamond is described by Milo March (Jack Palance) as: "$700,000 of unhappiness" because people are willing to do anything, even kill, to get it.Alan Ladd was originally announced to play the lead. Then Victor Mature was going to play it.
The combination of metals was a basic technique. Essentially, there is no such thing as 24 carat gold jewelry. Massive gold is the most malleable metal. It is almost like wax. In order to have jewelry that can pass the test of time and gravity, the Etruscans had to combine their gold with other metals.
Different diamond types react in different ways to diamond enhancement techniques. Different types can coexist within a single stone; natural diamonds are often mixes of Type Ia and Ib, which can be determined by their infrared absorption spectrum.Not restricted to type are "green" diamonds, whose color is derived from exposure to varying quantities of ionizing radiation.
Type I diamonds have nitrogen atoms as the main impurity, commonly at a concentration of 0.1%. If the nitrogen atoms are in pairs they do not affect the diamond's color; these are Type IaA. If the nitrogen atoms are in large even-numbered aggregates they impart a yellow to brown tint (Type IaB). About 98% of gem diamonds are type Ia, and most of these are a mixture of IaA and IaB material: these diamonds belong to the "Cape series", named after the diamond-rich region formerly known as Cape Province in North Africa, whose deposits are largely Type Ia. If the nitrogen atoms are dispersed throughout the crystal in isolated sites (not paired or grouped), they give the stone an intense "yellow" or occasionally "brown" tint (Type Ib); the rare "canary" diamonds belong to this type, which represents only 10% of known natural diamonds. Synthetic diamond containing nitrogen is Type Ib. Type I diamonds absorb in both the infrared and ultraviolet region, from . They also have a characteristic fluorescence and visible absorption spectrum (see Optical properties of diamond).
The DeYoung Red Diamond is a 5.03-carat unmounted diamond. It is a deep red color, with a slight tint of brown. Red diamonds are the rarest type of colored diamonds. The diamond is a modified round brilliant cut. The facets on the diamond's crown, which resemble kites, are split in two horizontally. This feature makes the DeYoung diamond more brilliant than other diamonds with an ordinary round brilliant cut. The DeYoung Red Diamond is the third-largest red diamond, behind only the 5.05-carat Kazanjian Red Diamond (second-largest) and the 5.11-carat Moussaieff Red Diamond (largest). Its clarity grade is VS-2 (Very Slightly Included). The diamond is a Type IIa diamond, meaning that it does not have any chemical impurities. Type IIa diamonds comprise only 1–2% of all naturally occurring diamonds.
Type II diamonds have no measurable nitrogen impurities. Type II diamonds absorb in a different region of the infrared, and transmit in the ultraviolet below , unlike Type I diamonds. They also 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 (1.8% of gem diamonds), but constitute a large percentage of Australian production. Type IIb diamonds, which account for 0.1% of gem diamonds, are usually light "blue" due to scattered boron within the crystal matrix; these diamonds are also semiconductors, unlike other diamond types (see Electrical properties of diamond). However, a blue-grey color may also occur in Type Ia diamonds and be unrelated to boron. Also 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.