|
Fineness
The fineness of a precious metal object (coin, bar, jewelry, etc.) represents the weight of ''fine metal'' therein, in proportion to the total weight which includes alloying base metals and any impurities. Alloy metals are added to increase hardness and durability of coins and jewelry, alter colors, decrease the cost per weight, or avoid the cost of high-purity refinement. For example, copper is added to the precious metal silver to make a more durable alloy for use in coins, housewares and jewelry. Coin silver, which was used for making silver coins in the past, contains 90% silver and 10% copper, by mass. Sterling silver contains 92.5% silver and 7.5% of other metals, usually copper, by mass. Various ways of expressing fineness have been used and two remain in common use: ''millesimal fineness'' expressed in units of parts per 1,000 and '' karats'' or ''carats'' used only for gold. Karats measure the parts per 24, so that 18 karat = = 75% and 24 karat gold is considered 100% go ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karat
The fineness of a precious metal object (coin, bar, jewelry, etc.) represents the weight of ''fine metal'' therein, in proportion to the total weight which includes alloying base metals and any impurities. Alloy metals are added to increase hardness and durability of coins and jewelry, alter colors, decrease the cost per weight, or avoid the cost of high-purity refinement. For example, copper is added to the precious metal silver to make a more durable alloy for use in coins, housewares and jewelry. Coin silver, which was used for making silver coins in the past, contains 90% silver and 10% copper, by mass. Sterling silver contains 92.5% silver and 7.5% of other metals, usually copper, by mass. Various ways of expressing fineness have been used and two remain in common use: ''millesimal fineness'' expressed in units of parts per 1,000 and '' karats'' or ''carats'' used only for gold. Karats measure the parts per 24, so that 18 karat = = 75% and 24 karat gold is considered 100% g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Per Mille
Per mille (from Latin , "in each thousand") is an expression that means parts per thousand. Other recognised spellings include per mil, per mill, permil, permill, or permille. The associated sign is written , which looks like a percent sign with an extra zero or o in the divisor. The term occurs so rarely in English that major dictionaries do not agree on the spelling and some major dictionaries such as '' Macmillan'' do not even contain an entry. The term is more common in other European languages where it is used to express fractions smaller than 1%. One common usage is blood alcohol content, which is usually expressed as a percentage in English-speaking countries. Per mille should not be confused with parts per million (ppm). Computer systems The code point for the glyph is included in the General Punctuation block of Unicode characters: .Unicode.General Punctuation. 2014. Accessed 5 Aug 2014. It may be typed using , , , or according to operating system. Note that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sterling Silver
Sterling silver is an alloy of silver containing 92.5% by weight of silver and 7.5% by weight of other metals, usually copper. The sterling silver standard has a minimum millesimal fineness of 925. ''Fine silver'', which is 99.9% pure silver, is relatively soft, so silver is usually alloyed with copper to increase its hardness and strength. Sterling silver is prone to tarnishing, and elements other than copper can be used in alloys to reduce tarnishing, as well as casting porosity and firescale. Such elements include germanium, zinc, platinum, silicon, and boron. Recent examples of these alloys include ''argentium'', ''sterlium'' and ''silvadium''. Etymology One of the earliest attestations of the term is in Old French form , in a charter of the abbey of Les Préaux, dating to either 1085 or 1104. The English chronicler Orderic Vitalis (1075 – 1142) uses the Latin forms and . The word in origin refers to the newly introduced Norman silver penny. According to the Oxford Eng ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hallmark
A hallmark is an official mark or series of marks struck on items made of metal, mostly to certify the content of noble metals—such as platinum, gold, silver and in some nations, palladium. In a more general sense, the term ''hallmark'' can also be used to refer to any distinguishing mark. General overview Historically, hallmarks were applied by a trusted party: the "guardians of the craft" or, more recently, by an assay office. Hallmarks are a guarantee of certain purity or fineness of the metal, as determined by official metal (assay) testing. Distinguishment Hallmarks are often confused with "trademarks" or "maker's marks". A hallmark is not the mark of a manufacturer to distinguish their products from other manufacturers' products: that is the function of trademarks or makers' marks. To be a true hallmark, it must be the guarantee of an independent body or authority that the contents are as marked. Thus, a stamp of "925" by itself is not, strictly speaking, a hallmark, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Per Mil
Per mille (from Latin , "in each thousand") is an expression that means parts per thousand. Other recognised spellings include per mil, per mill, permil, permill, or permille. The associated sign is written , which looks like a percent sign with an extra zero or o in the divisor. The term occurs so rarely in English that major dictionaries do not agree on the spelling and some major dictionaries such as '' Macmillan'' do not even contain an entry. The term is more common in other European languages where it is used to express fractions smaller than 1%. One common usage is blood alcohol content, which is usually expressed as a percentage in English-speaking countries. Per mille should not be confused with parts per million (ppm). Computer systems The code point for the glyph is included in the General Punctuation block of Unicode characters: .Unicode.General Punctuation. 2014. Accessed 5 Aug 2014. It may be typed using , , , or according to operating system. Note that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Good Delivery
The Good Delivery specification is a set of rules issued by the London Bullion Market Association (LBMA) describing the physical characteristics of gold and silver bars used in settlement in the wholesale London bullion market. It also puts forth requirements for listing on the LBMA Good Delivery List of approved refineries. Good Delivery bars are notable for their large size and high purity. They are the type normally used in the major international markets (Hong Kong, London, New York, Sydney, Tokyo, and Zürich) and in the gold reserves of governments, central banks, and the IMF. ''The Good Delivery Rules for Gold and Silver Bars'' The entire Good Delivery specification is contained in the LBMA document titled ''The Good Delivery Rules for Gold and Silver Bars: Specifications for Good Delivery Bars and Application Procedures for Listing''. The document includes specific requirements regarding the fineness, weight, dimensions, appearance, marks, and production of gold and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable metallic form ( native metals). This led to very early human use in several regions, from circa 8000 BC. Thousands of years later, it was the first metal to be smelted from sulfide ores, circa 5000 BC; the first metal to be cast into a shape in a mold, c. 4000 BC; and the first metal to be purposely alloyed with another metal, tin, to create ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perth Mint
The Perth Mint is Australia's official bullion mint and wholly owned by the Government of Western Australia. Established on 20 June 1899, two years before Australia's Federation in 1901, the Perth Mint was the last of three Australian colonial branches of the United Kingdom's Royal Mint (after the now-defunct Sydney Mint and Melbourne Mint) intended to refine gold from the gold rushes and to mint gold sovereigns and half-sovereigns for the British Empire. Along with the Royal Australian Mint, which produces coins of the Australian dollar for circulation, the Perth Mint is the older of Australia's two mints issuing coins that are legal tender. History Perth Mint, as a business entity, was established during the 1890s, as a subsidiary of the Royal Mint in the United Kingdom. The foundation stone of the Mint building was laid in 1896 by Sir John Forrest. The building was officially opened on 20 June 1899. At that time, the population of Western Australia (WA) was growing rapid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impurity
In chemistry and materials science, impurities are chemical substances inside a confined amount of liquid, gas, or solid, which differ from the chemical composition of the material or compound. Firstly, a pure chemical should appear thermodynamically in at least one chemical phase and can also be characterized by its one-component-phase diagram. Secondly, practically speaking, a pure chemical should prove to be homogeneous (i.e., will show no change of properties after undergoing a wide variety of consecutive analytical chemical procedures). The perfect pure chemical will pass all attempts and tests of further separation and purification. Thirdly, and here we focus on the common chemical definition, it should not contain any trace of any other kind of chemical species. In reality, there are no absolutely 100% pure chemical compounds, as there is always some minute contamination. Indeed, as detection limits in analytical chemistry decrease, the number of impurities detected tend ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile metal in a pure form. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions. Gold often occurs in free elemental ( native state), as nuggets or grains, in rocks, veins, and alluvial deposits. It occurs in a solid solution series with the native element silver (as electrum), naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium (gold tellurides). Gold is resistant to most acids, though it does dissolve in aqua regia (a mixture of nitric acid and hydrochloric acid), forming a soluble tetrachloroaurate anion. Gold is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crown Gold
Crown gold is a 22 karat (kt) gold alloy used in the crown coin introduced in England in 1526 (by Henry VIII). In this alloy, the proportion of gold is 22 parts out of 24 (91.667% gold)—and is appreciably less prone to wear than the softer 23 kt gold of earlier gold sovereigns—an important point for coins intended for everyday use in circulation. Alloying metal The alloying metal in England was, and is, traditionally restricted to copper. This is still used for the current British gold sovereign. An exception was for the gold sovereigns of 1887, when 1.25% silver, replacing the same weight of copper, was used to gain a better reproduction image of Queen Victoria for the Golden Jubilee of her reign. Elsewhere, both copper and silver have been used in varying proportions. Circulating coins In the United States until 1834, gold circulating coins were minted in 22 kt. crown gold—although using about 6% silver as well as copper. From 1834, the fineness of U.S. coin gold was decr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ducat
The ducat () coin was used as a trade coin in Europe from the later Middle Ages from the 13th to 19th centuries. Its most familiar version, the gold ducat or sequin containing around of 98.6% fine gold, originated in Venice in 1284 and gained wide international acceptance over the centuries. Similarly named silver ducatons also existed. The gold ducat circulated along with the Florentine florin and preceded the modern British pound sterling and the United States dollar. Predecessors The word ''ducat'' is from Medieval Latin ''ducalis'' = "relating to a duke (or dukedom)", and initially meant "duke's coin" or a "duchy's coin". The first issue of scyphate billon coins modelled on Byzantine ''trachea'' was made by King Roger II of Sicily as part of the Assizes of Ariano (1140). It was to be a valid issue for the whole kingdom. The first issue bears the figure of Christ and the Latin inscription ''Sit tibi, Christe, datus, quem tu regis iste ducatus'' (meaning "O Christ, let thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
