METALLURGY DATA SHEET FOR COINS AND BULLION

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  FINE; 99.99 or 99.999

  100 MILLS GOLD or SILVER; A bar or coin described as "1oz 100 mills GOLD!!!!" contains one ounce of base metal, layered with gold to only 100 millionths of an inch deep (0.0001 inches of gold). In layering, "mill" does indeed stand for millionths of an inch of gold.

  .99 OR .999; 1% or less in content

  PURE; 99.99 or 99.999

  24KT; Is not pure gold and has a lower value than pure 99.99 gold market price

  22KT; Is not pure gold and has a lower value than pure 99.99 gold market price

  18KT; Is not pure gold and has a lower value than pure 99.99 gold market price

  9KT; Is not pure gold and has a lower value than pure 99.99 gold market price

  GOLD ALLOY; Can have from 99.000% down to 0.001% gold

  ALLOY;  An alloy is a metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal (heat treatment) history. Alloys usually have different properties from those of the component elements.
Alloy constituents are usually measured by mass.

  BI METAL: Bi-metal refers to an object that is composed of two separate metal s joined together. mixture of two or more metals, like alloy

  GOLD; Gold is a chemical element with the symbol Au (from Latin: ("gold") and an atomic number of 79. Gold is a dense, soft, shiny metal and the most malleable and ductile metal known. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a transition metal and a group 11 element. With exception of the noble gases, gold is the least reactive chemical element known. It has been a valuable and highly sought-after precious metal for coinage, jewelry, and other arts since long before the beginning of recorded history.
Gold resists attacks by individual acids, but it can be dissolved by the aqua regia, so named because it dissolves gold. Gold also dissolves in alkaline solutions of cyanide, which have been used in mining. Gold dissolves in mercury, forming amalgam alloys. Gold is insoluble in nitric acid, which dissolves silver and base metals, a property that has long been used to confirm the presence of gold in items.

  WHITE GOLD; White gold is an alloy of gold and at least one white metal, usually nickel, manganese or palladium. Like yellow gold, the purity of white gold is given in karats.
White gold's properties vary depending on the metals and proportions used. As a result, white gold alloys can be used for many different purposes; while a nickel alloy is hard and strong and therefore good for rings and pins, gold-palladium alloys are soft, pliable and good for white gold gemstone settings, sometimes with other metals like copper, silver, and platinum for weight and durability, although this often requires specialized goldsmiths. The term white gold is used very loosely in the industry to describe karat gold alloys with a whitish hue. Many believe that the color of the rhodium plating, which is seen on many commercial pieces, is actually the color of white gold. The term "white" covers a large spectrum of colors that borders or overlaps pale yellow, tinted brown, and even very pale rose. The jewelry industry often hides these off-white colors by rhodium plating.
A common white gold formulation consists of 90 wt.% gold and 10 wt.% nickel.[1] Copper can be added to increase malleability.[2]
The strength of gold-nickel-copper alloys is caused by formation of two phases, a gold-rich Au-Cu, and a nickel-rich Ni-Cu, and the resulting hardening of the material.[2]
The alloys used in jewelry industry are gold-palladium-silver and gold-nickel-copper-zinc. Palladium and nickel act as primary bleaching agents for gold; zinc acts as a secondary bleaching agent to attenuate the color of copper.

  GOLD PLATING; Gold plating is a method of depositing a thin layer of gold onto the surface of another metal, most often copper or silver (to make silver-gilt), by chemical or electrochemical plating. This article covers plating methods used in the modern electronics industry; for more traditional methods, often used for much larger objects

  GOLD FILLED; Gold-filled, also known as "rolled gold" or "rolled gold plate" is composed of a solid layer of gold bonded with heat and pressure to a base metal such as brass. Some high quality gold-filled pieces have the same appearance as 14 karat (58%) gold. In the USA the quality of gold filled is defined by the Federal Trade Commission. If the gold layer is 10 kt fineness the minimum layer of karat gold in an item stamped GF must equal at least 1/10 the weight of the total item. If the gold layer is 12 kt or higher the minimum layer of karat gold in an item stamped GF must equal at least 1/20 the weight of the total item. The most common stamps found on gold-filled jewelry are 1/20 12kt GF and 1/20 14kt GF. Also common is 1/10 10kt. Some products are made using sterling silver as the base, although this more expensive version is not common today.

  ROLLED GOLD; Rolled Gold, also known as "gold-filled" or "rolled gold plate" is composed of a solid layer of gold bonded with heat and pressure to a base metal such as brass. Some high quality gold-filled pieces have the same appearance as 14 karat (58%) gold. In the USA the quality of gold filled is defined by the Federal Trade Commission. If the gold layer is 10 kt fineness the minimum layer of karat gold in an item stamped GF must equal at least 1/10 the weight of the total item. If the gold layer is 12 kt or higher the minimum layer of karat gold in an item stamped GF must equal at least 1/20 the weight of the total item. The most common stamps found on gold-filled jewelry are 1/20 12kt GF and 1/20 14kt GF. Also common is 1/10 10kt. Some products are made using sterling silver as the base, although this more expensive version is not common today.

  GOLD LAYERED; Gold Layering of brass or silver is used in the manufacture of jewelery. Like copper, silver atoms diffuse into the gold layer, causing slow gradual fading of its color and eventually causing tarnishing of the surface. This process may take months and even years, depending on the thickness of the gold layer. A barrier metal layer is used to counter this effect. Copper, which also migrates into gold, does so more slowly than brass or silver. The copper is usually further plated with nickel. A gold-plated silver article is usually a silver substrate with layers of copper, nickel, and gold deposited on top of it.

  SILVER; Silver is a metallic chemical element with the chemical symbol Ag (Latin: argentum, from the Indo-European root *arg- for "grey" or "shining") and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal. The metal occurs naturally in its pure, free form (native silver), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a byproduct of copper, gold, lead, and zinc refining.
Silver has long been valued as a precious metal, and it is used to make ornaments, jewelry, high-value tableware, utensils (hence the term silverware), and currency coins. Today, silver metal is also used in electrical contacts and conductors, in mirrors and in catalysis of chemical reactions. Its compounds are used in photographic film and dilute silver nitrate solutions and other silver compounds are used as disinfectants and microbiocides. While many medical antimicrobial uses of silver have been supplanted by antibiotics, further research into clinical potential continues.

  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 (99.9% pure) is generally too soft for producing functional objects; therefore, the silver is usually alloyed with copper to give it strength but preserving the ductility and beauty of the precious metal. Other metals can replace the copper, usually with the intent to improve various properties of the basic sterling alloy such as reducing casting porosity, eliminating firescale, and increasing resistance to tarnish. These replacement metals include germanium, zinc and platinum, as well as a variety of other additives, including silicon and boron. A number of alloys, such as Argentium sterling silver have appeared in recent years, formulated to lessen firescale or to inhibit tarnish, and this has sparked heavy competition among the various manufacturers, who are rushing to make claims of having the best formulation. However, no one alloy has emerged to replace copper as the industry standard, and alloy development is a very active area.

  925 SILVER; 925 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 (99.9% pure) is generally too soft for producing functional objects; therefore, the silver is usually alloyed with copper to give it strength but preserving the ductility and beauty of the precious metal. Other metals can replace the copper, usually with the intent to improve various properties of the basic sterling alloy such as reducing casting porosity, eliminating firescale, and increasing resistance to tarnish. These replacement metals include germanium, zinc and platinum, as well as a variety of other additives, including silicon and boron. A number of alloys, such as Argentium sterling silver have appeared in recent years, formulated to lessen firescale or to inhibit tarnish, and this has sparked heavy competition among the various manufacturers, who are rushing to make claims of having the best formulation. However, no one alloy has emerged to replace copper as the industry standard, and alloy development is a very active area.

  FINE SILVER; Silver is a metallic chemical element with the chemical symbol Ag (Latin: argentum, from the Indo-European root *arg- for "grey" or "shining") and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal. The metal occurs naturally in its pure, free form (native silver), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a byproduct of copper, gold, lead, and zinc refining.
Silver has long been valued as a precious metal, and it is used to make ornaments, jewelry, high-value tableware, utensils (hence the term silverware), and currency coins. Today, silver metal is also used in electrical contacts and conductors, in mirrors and in catalysis of chemical reactions. Its compounds are used in photographic film and dilute silver nitrate solutions and other silver compounds are used as disinfectants and microbiocides. While many medical antimicrobial uses of silver have been supplanted by antibiotics, further research into clinical potential continues.

  SILVER BULLION; Silver coins are possibly the oldest mass produced form of coinage. Silver has been used as a coinage metal since the times of the Greeks. Their silver drachmas were popular trade coins.
As with all collectible coins, many factors determine the value of a collectible silver coin, such as its rarity, demand, condition and the number originally minted. Ancient silver coins coveted by collectors include the Denarius and Miliarense, while more recent collectible silver coins include the Morgan Dollar and the Spanish Milled Dollar.
Other than collector's silver coins, silver bullion coins are popular among people who desire a "hedge" against currency inflation or store of value. Silver has an international currency symbol of XAG under ISO 4217.
Before 1797, British pennies used to be made out of silver while the ancient Persians used silver coins between 612-330 BC

  GERMAN SILVER; German silver, also known as Nickel silver, Argentann, paktong, new silver, nickel brass, or alpacca (or alpaca), is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. In fact, all modern, commercially important nickel silvers (such as those standardized under ASTM B122) contain significant amounts of zinc, and are sometimes considered a subset of brass.
Nickel silver is named for its silvery appearance, but contains no elemental silver unless plated

  NICKEL SILVER; Nickel silver, also known as German silver, Argentann, paktong, new silver, nickel brass, or alpacca (or alpaca), is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. In fact, all modern, commercially important nickel silvers (such as those standardized under ASTM B122) contain significant amounts of zinc, and are sometimes considered a subset of brass.
Nickel silver is named for its silvery appearance, but contains no elemental silver unless plated

  TIBETAN SILVER; Tibetan silver is used primarily in jewellery components, and is similar to pewter - an alloy of copper, and sometimes tin or nickel, with a small percentage of pure silver. Its overall appearance is of aged silver, but it can be polished to provide highlights on complex castings. The nickel content is nowadays reduced or absent, due to common allergies to this metal.
Tibet silver used to have a higher silver content a decade or two ago, up to 30% or higher, but cheaper reproductions from Far Eastern factories have diluted the term. The genuine article can only really be got from the metal and silversmiths in situ, some of whom still manage to produce work from their long tradition of gold and silversmithing in this country. The related term 'Nepalese silver', however, seems to have held on to the higher silver content and association with quality metalsmithing.
Currently, jewellery, beads and castings described as 'Tibetan Silver' tends to be a base iron 'cheese metal' casting, overlaid with this pewter and silver plating. Dependent on source, these can be either thick and robust, or attractive but easily broken due to a loose, fragile inner casting. The latter productions are therefore only suitable for small castings up to around 12mm, or transient 'fashion' jewellery with a short lifespan.
Metallurgical testing of twelve items in 2007 offered for sale on eBay as Tibetan Silver indicated that the articles frequently contained no silver whatsoever. Tests also found that high levels of lead and other dangerous metals such as arsenic were present

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