Alloy: An alloy is a combination of two or more metals. Common alloys used in jewelry are gold under 24 Kt (mixed with silver, copper, and/or other metals), sterling silver (92.5% silver, 7.5% copper), brass (roughly half copper, half zinc), bronze (at least 60% copper with tin and perhaps other metals), and pewter (tin, lead, antimony, and a bit of silver or copper).
Annealing: A heating process to soften precious metals.
Anode: Positive electrode supplying metal in electroplating, electroforming, electrolysis process.
Aqua Regia: A mixture by mixing concentrated nitric acid and hydrochloric acid in a volume ratio of 1:3. It is commonly used in testing the fineness of gold.
Assay: A test to determine the quality and purity of a gold or silver product. When a gold or silver product ship with an “assay”, this is a guarantee from the assayer that the product in question does indeed contain the described amount and purity of gold or silver.
Au: The chemical symbol for gold which is derived from “aurum”, the Latin word for gold.
Bar: A mass of metal cast or shaped into a convenient shape. It is a generic term for a bar of gold or silver and a non-numismatic form of precious metal bullion.
Base Metal: Metals which are commonly used to alloy gold jewelry, e.g., copper, silver, zinc, nickel, platinum, and palladium.
Bullion: Traditionally stands for precious metals bars or ingots, such as gold bullion and silver bullion which are officially recognized as being at least 99.5% purity and are in the form of bars or ingots rather than coins. In the United States, the most commonly traded gold bullion pieces among individual investors weigh 10 oz. or less.
Carat: (with a “c”) A measurement of weight which is generally used in reference to gems. It is equal to about 3.086 grains Troy or 0.2 grams. It is not to be confused with KARAT (with a “k”) which is a measurement of the fineness of gold.
Casting: Gold casting is a part of the jewelry creation process. It allows designers and jewelry stores to take an idea or design, create a mold, and eventually end up with a physical reproduction of the final product.
Certified Gold: A “certified” gold coin is encapsulated in a tamper-proof, sonically sealed, high-security hard plastic holder, with a unique certification number and bar-code permanently sealed inside each coin capsule for the protection of the investor.
Coin: A stamped piece of metal of a known weight and fineness issued for commerce.
Coin Gold: In the United States, it was an alloy of 9 parts gold, 1 part copper.
Crown Gold: It describes an 18-karat gold alloy.
Crucible: Made of high-grade heat-resistant materials and contains gold, silver, etc. Container for melting ores, tailings, and mineral mixtures.
Cu: The metallurgical symbol for copper.
Cupel: A small shallow porous cup especially of bone ash used in assaying to separate precious metals from lead
Cupellation: Separation of gold or silver from impurities by melting the impure metal in a cupel (a flat, porous dish made of a refractory material) and directing a blast of hot air on it in a special furnace. The impurities, including lead, copper, tin, and other unwanted metals, are oxidized, and partly vaporized and partly absorbed into the pores of the cupel
Doré bullion: A impure alloy silver contains a variable but usually appreciable percentage of gold.
Drittel Gold: In German, Drittel means 1/3. Drittel Gold is an 8-karat gold alloy.
E-Gold: E-gold is nothing, but gold held by investors in electronic form (demat form) similar to holding shares. E-Gold is one of the most price effective methods to invest in gold.
Electroplate: Process by which 24 karat gold is deposited on another metal electrolytically. The plating must be at least seven millionths of an inch thick.
Fine Gold: Indicates the fineness or purity of a gold coin or gold bullion. It means the gold item is a pure gold, 24 karat, or .999 fine gold.
Fine Silver: Indicates the fineness or purity of a silver coin or silver bullion. It means the silver item is a pure silver, 99.9% or higher pure.
Fire Assay: Fire assay is considered the most reliable method for accurately determining the content of gold, silver, and platinum group metals (except osmium and ruthenium) in ores or concentrates. This process involves melting a gold-containing sample in a clay crucible with a mixture of fluxes, lead oxide and a reducing agent.
French Gold: (or Oreide) is a copper alloy that is made of 80% copper, 15% zinc and 5% tin used to imitate gold.
Furnace: The place where metals such as gold and silver are placed in a crucible and melted. Since high heat is required to melt gold and silver, coal is used in the furnace. The used metal is purified from other impurities and the metal that becomes liquid is poured into molds with the same tongs.
Granulation: An ancient technique in which very small spheres are attached to a surface as ornament. In proper granulation the filler that joins the parts is so small it is invisible to the naked eye, creating the illusion that the tiny balls are simply set in place.
Hera Gold: It is a German name for a 10-karat gold alloy.
Induction Furnace: The electric furnace is the best option for melting pure gold. Induction furnace is the best option as pure gold does not contain impurities and furnace is only used for melting and forming purposes. It melts in a very short time and pours easily.
Jewelry: An adornment (as a bracelet or ring or necklace) made of precious metals and set with gems (or imitation gems).
Jou-Jou Or: It is, from French: “toy gold”, a 6-karat gold alloy.
Gilt: It is a base metal with an extremely thin gold coating (a process known as gilding) that is deposited chemically or electrically to give an inexpensive product the appearance of gold.
Gold: Gold is a precious metal which is found in nature. In its purest form it is a bright, slightly orange yellow which is quite soft and malleable. It is one of the least reactive chemical elements, making it highly prized in jewelery making as it will barely tarnish and isn’t affected by most chemicals.
Gold À Quatre Couleurs: It refers to the combination of four different shades of gold alloy used in a single jewelry item. To create harmonious design, colors are inlaid and soldered. The combination of green, red, white, and blue gold was the most commonly used mixture in jewelry design. The technique gained popularity after 1750.
Gold Color: Variations in the alloys used with gold create different colors of gold such as yellow, green, red, and white. The most common alloys used with gold are silver, copper, zinc, and nickel. Silver and zinc tend to give gold a greenish hue, copper a reddish cast and nickel a white color.
Gold Electrolysis: Gold electrolysis is used to obtain five zero gold. 99.99% pure gold is fed to the electrolysis and 99.999% pure gold is produced.
Gold Filled: A mechanical process of plating gold on another metal. This can be done by brazing, soldering, welding, etc. The plating must be at least 1/20th of the weight of the metal in the entire item.
Gold Leaf: It is the result of ancient gold forging art, where a gold nugget was reduced by a rolling mill to 1/800 of an inch thick to create a gold strip. This strip is cut into 1-inch lengths, placed in a mold, and hammered with a 16-pound hammer. The gold is cut and hammered many times until it is extremely fine. The resulting gold layers can be used for objects, furniture, walls, paintings, sculptures, etc.
Gold Melting: In its natural state or in an undesirable jewelry box, “pure” gold of various shapes and sizes is melted at the melting temperature of the gold and poured into a mold and given the desired shape. Its chemical content does not change.
Gold Plate: Items that are gold plated are coated with gold by the processes that produce gold-filled or rolled gold plate.
Gold-Plated Jewelry: Gold plated jewelry is made through a process where another metal is covered with a very thin layer of gold through electroplating.
Gold Standard: A monetary system based on convertibility into gold; paper money backed and interchangeable with gold.
Gold-Silver Ratio: It is the number of ounces of silver required to purchase one ounce of gold.
Gold Smudge: A gold smudge is a colored smudge, left by jewelry or another metallic object, on the skin of the wearer. Although precious metals are usually non-reactive, in rare cases they may react with the environment. Usually, these special cases involve chemical reactions between the skin of the wearer and the metal, or the alloy, as is sometimes the case during pregnancy or with people who are allergic to that metal. Cosmetics, detergents, pollution, and other such factors can also be culprits in causing “gold smudge”.
Gold Wash: Gold wash refers to a gilded layer with a thickness of less than 0.2 micron.
Green Gold: Green gold is an alloy with silver that is usually 75 percent gold and 25 percent fine silver. Green gold can be made with less silver, but it usually includes zinc and copper along with the silver.
Grey Gold: Grey gold is an alloy of gold and iron or gold, silver, and iron that is a pale grey color.
Ingot: An ingot is a form of gold bar, which gets its name from the mould in which the bar is cast
Karat: A unit of purity for gold alloys, rather than weight. The word “karat” is from the carob seed, which was used as balance scales to measure the weight of gold in ancient Asian bazaars. Pure gold is considered to be 24 karat.
Karat Gold: A gold alloy mixed with other metals, such as silver, copper, or zinc. It is used in the manufacture of jewelry. The higher the karat, the higher the gold content in the item. In U.S., the gold jewelry must be at least 10 karats, otherwise it cannot be called gold.
Kilo bar: A bar weighing one kilogram (32.1507 troy ounces). The preferred bar size for gold investment in India and China. Requires melting and recasting of the wholesale market’s larger 400-ounce Good Delivery bars. Chinese demand also tends towards higher purity than the London standard of 995 parts per thousand, preferring 999 parts.
Ingot: A mass of metal cast into a convenient shape. In the precious metals industry, the words ingot, and bar are used interchangeably.
London Fixing Price: A precious metal price which is fixed by the London Gold Market Fixing Ltd via conference call, which is used as a benchmark pricing the major global precious metal products and derivatives. The gold fixing price is fixed twice each business day at 10:30 am and 3 pm, and the silver price fixing is set or fixed once a day, at 12:00 am London local time.
London Gold or LOCO London: A way of gold trading. In a narrow sense, London gold is a traded product provided by the London International Financial Futures Exchange and stored in the city of London underground vault in a purity of 99.5% with 400 ounces of gold bricks. Broadly speaking, London gold represents all of spot gold trading.
Metric ton: 1,000 kilograms or 32,151 troy ounces.
Mine: To dig in the earth for the purpose of extracting ores or other valuable minerals.
Miner: A person who works in a mine.
Micron: A unit of length equal to one millionth of a meter, used in many technological and scientific fields.
Mold: The mold or container in which molten metal is cast and allowed to solidify in order to form an ingot.
Nugget: Modern gold bullion coin minted by Australia, .9999 fine.
Ounce: A unit of weight. In the precious metals industry, an ounce means a troy ounce equal to 31.1035 grams.
Ore: A mineral-bearing rock, which may be rich enough to be mined at a profit.
Oxidation: The forming of an oxide from base metals such as the copper in sterling silver or a karat gold alloy combining, through heat, with oxygen and forming a coating of copper oxide. Not to be confused with the discoloration of silver by sulphur and its compounds.
Quartz: Metal encased in rock.
Palladium: Stronger than white gold, palladium is a pure white metal from the platinum family.
Paper gold / Paper silver: Ownership of gold or silver which is not tangible.
Pistol Gold: It is a gold alloy with 895/1000 parts of gold.
Platinum: A white metal, and one of the hardest and more popular metals used in engagement rings today.
Polishing: The smoothness of the facets of a diamond. Smoother facets reflect light more acutely and increase brilliance.
Precious Metals: Metals prized because of chemical and physical properties such as resistance to corrosion, hardness, strength, and beauty. Common precious metals used for making jewelry are platinum, gold, silver, and palladium.
Purity: The gold or silver content contained within a bar, round, or coin. Usually displayed as .XXX. Ex – .999 1 Ounce Silver Bars, indicating 99.9% purity.
Raw Gold: Bullion coins that have not been certified or encapsulated.
Recycling: Recycling refers to the sale by individuals of their privately held gold back into the market, to be refined back into bullion. This specifically refers to gold sold for cash. It does not include gold traded-in for other gold products (for example, by consumers at jewellery stores) or process scrap (working gold that never becomes part of a fabricated product but instead returns as scrap to a refiner).
Refinery: Where precious metals are purified and prepared for being made into coins and bars.
Refining: Operations performed to extract metals in pure form from masses containing other metals or impurities.
Reserves: Mining companies will estimate how much gold remains at each mining project they operate. These can be split into two categories: reserves (gold that is economic to mine at the prevailing gold price); and resources (gold that will potentially be economic to mine, subject to further investigation or at a difference price level).
Resources: Mining companies will estimate how much gold remains at each mining project they operate. These can be split into two categories: reserves (gold that is economic to mine at the prevailing gold price); and resources (gold that will potentially be economic to mine, subject to further investigation or at a difference price level).
Rhodium (Rh): A white metallic element of the platinum group, commonly used as an electroplate finish on white gold to improve the white color.
Roman Gold: is a technique that uses the matting or frosting process followed by electroplating with pure gold. This results in a soft rich yellow without being polished.
Rose Gold: Rose gold jewellery is created with an alloy of gold and copper, with the copper content providing the altered colour to yellow gold. Rose gold is also known as pink gold and red gold, but the different names usually relate to the amount of copper used: the higher the copper content, the stronger the red coloration.
Scrap: A class of jewelry-shop waste, cuttings of precious metals, large enough to sort for re-melting; differentiated from filings, sawdust and other small waste that has to be sweep-smelted and refined to recover it for use.
Silver: A soft, white, and lustrous precious metal which is found in nature. It has the highest reflectivity of any metal and is frequently used to make high value jewellery and other decorative items. Especially when making jewellery it’s usually alloyed with copper to make it stronger (sterling silver).
Slag: The waste left as a residue by the smelting of metallic ore.
Stamp Mill: A mill or machine in which ore is crushed to powder by means of heavy stamps or pestles.
Smelting: It is a way to extract many metals from their ores, including silver, iron, gold etc. The process involves the use of heat and chemical reducing agents to decompose the ore. All other elements get removed as gases or slag leaving behind the desired metal.
Smelting Gold: It refers to “burning off” the impurities that gold might be mixed with, resulting in nearly pure gold. If there is a gold mixed with black sand or other impurities that it need to be mix with flux and smelt for get rid of the impurities.
Tempering: Increasing the hardness of metal by gradual heating to stages less than annealing heat.
Tri-Color Gold: Tricolor gold is the use of three colors of gold in jewelry fabrication. Usually, this is a combination of yellow, white and rose or green gold.
White Gold: This is gold which is alloyed with other metals to have a colour closer to silver than typical yellow gold. The other metals used may be manganese, nickel, or palladium. Note that real white gold does not have the bright white finish you’ll see in many jewellery stores: it’s usually more of a warm grey colour. The bright white finish is most often achieved by plating the white gold with rhodium, which will wear off over time and need replacing.
Yellow Gold: The most popular alloy of gold. Pure gold is very soft and very difficult to use for jewelry. Alloys can be added to yellow gold to make it strengthen and create a harder, more workable alloy. It is typical alloys are a mixture of gold, silver, copper and sometimes zinc.
Zinc: A bluish-white metal, melting point, 787º F; used in gold alloys to lower the melt temperature and improve malleability.