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Abrasion index - measures how abrasive a rock type is with respect to either wear and tear on grinding
equipment or wear by frictional forces such as wave action.

Accolated -  A design where two or more heads both face the same direction and overlap each other.

Accumulation - A collection or hoard of coins or other object.

Acetate -  Modern coin holders, such as manufactured by Dansco, have acetate slides - a type of plastic that allows you to see the coins in the holder slot through the slide while protecting the coin from atmospheric and chemical damage.

Acid drainage - when rainwater reacts with existing sulfides in waste rock such that runoff exhibits acidic characteristics (pH below 7, typically below 5).

Adjustment - The filing down of a planchet or die to correct errors in size, shape or weight.

Aes, As - Roman word for bronze. Typically refers to a cast bronze coin from the Roman Republic.

Ag - silver

A.k.a. - 'also known as'; a synonym

Al - aluminum

Alloy - A mixture of more than one metal.  The naming convention typically uses the name of the most predominant or valuable metal in the mixture, for example, such as 'cupro-nickel' or 'nickel alloy'.

Altered - Describes a coin that has been intentionally manipulated to make the coin more valuable through change to appearance or design.

am - Adjustment marks; light surface filing performed at the mint to reduce an overweight planchet.

American Eagle - ((alt: American Silver Eagle, ASE, SAE) The US gold bullion coin produced by the US mint. Face amounts are 50 20, 10 and five dollars with corresponding weights of 1 oz., 1/2 oz., 1/4 oz. and 1/10 oz..

American Numismatic Association - The largest numismatic hobby society:

American Numismatic Society - A New York organization focused mainly on coins and medals.

ANACS - American Numismatic Association Certification Service

Ancient (coin) - Typically refers to a coin produced before the date A.D. 500

Annealing – This process is used in metal working to heat and temper metal into a less brittle form for working and molding. 

Anvil Die - The die opposable to the striking die; the die where the blank rests just prior to the strike.

Arbitrage - When one simultaneously buys and sells a commodity or other financial securities at different bourses or in different forms to take advantage of existing or anticipated price differentials.

Archaean - The older time division of the Precambrian; over 2,500 million years old.

Artificial Color - Chemicals added to a coin's surface to change the oxidized coin from a more natural brown to a less common (but more valuable)  red color.

Artificial Toning  - The process when chemicals added to a coin's surface to change the appearance, gradually, in an attempt to increase the perceived market value of the coin.

Artisanal  -  Primitive mining methods. Or, hand made method.

Ask Price - The retail selling price offered by the dealer to a member of the public (aka "wholesale", "sell" or "offer" price).

Assay - Physical and chemical analytical tests that determine the consistency, fineness and weight of precious or other metal in ore, soils, bullion or coin.

Assay laboratory - A laboratory in which the proportions of metal in ores or concentrates are determined using analytical techniques

Attribution - The process of identifying diagnostics, or unique elements of a piece, artifact or coin, and the ascribing of production means, age, and composition into the field literature.  Also refers to this initial reference or heritage.

Authentication - A certification or determination of the genuineness; an attribution of type or heritage.


Back - The reverse of a paper currency note.

Back-fill - Material used to replace soil and earth removed during mining operations

Bacterial leaching / bio-oxidation - The use of bacteria to oxidize sulphide minerals

Bag – A burlap container full of coins sealed by the US Mint or a bank.

Bag mark – A scratch, ding, or other mark detracting from the appeal and value of the coin made during loading or transport of the bag.  The coins clashed against each other causing these marks.

Bands - A diagnostic feature of a coin such as the horizontal bands across the fasces on the winged liberty ('Mercury') dime. Or, alternating geologic strata.

Bank Note - Currency produced and backed ('promissory', 'bearer', 'demand') by US banks in the 19th and 20th centuries.

Bankable Feasibility Study  - Study that determines the proven and probably reserves of a mining company.

Barber, Charles - Former Chief Engraver of the US Mint.

bas relief - A model sculpture with differences between the raised design and the field.  The model used to produce coins and medals.

Base - Chemical term describing a substance with a pH above 7.0

Base Metal - An alloy, or mixture, of non-precious metals used for financial or industrial applications. Might be used under gold or silver-plated coverings.

Basining - A step in the coin minting process where the die surfaces are set against a rotating zinc plate; polishing of the die. This process helps the coin properly strike.

Bid Price - The price a dealer is willing to pay (aka "buy" price) from either the public (retail) or another dealer (wholesale).

Bid Sheet - The format of an information sheet used to buy coins at auction, mail order, or at a brick and mortar store. THese numbers represent the price the buyer is willing to pay.

Bid-buy Sale - The combination of fixed-price and mail-bid sales where customers may either buy outright at a fixed price or place an alternate bid for the sellers consideration.

Bilon - A silver copper alloy used in coinage.

Billon – A coin with more copper than silver; potentially comprised of other metals.

Bio-oxidation - A processing method where bacteria oxidizes refractory sulfide ore such that it is then amenable
to normal oxide ore processing techniques.

Bison - A north American buffalo used as a design on US coins.

Bit - The Spanish Reale, a circulating silver coin that functioned equivalent to the value unit of a dollar broken into 8 parts. Each of these eights was on bit. Origination of the term 'two-bits' to represent a quarter-dollar.

Blank - See planchet.

Blazer - Slang for a brilliant white coin.

Blue Book - The Handbook of United States Coins, called the 'blue book" for short since it has a blue cover. This book provides wholesale coin prices that a dealer may offer.

Blue Ikes - %40 silver Eisenhower dollars sent by U.S. Mint in blue envelopes.

Block -   a series of related notes (paper money) with the same prefix and suffix letters in the serial number.  A new block is created with different suffix series (when the serial number reaches 99,920, 000).

Bluesheet - The Certified Coin Dealer Newsletter which list prices for graded coins.

Bullion - Precious metals in a known, negotiable and tradable form, such as a bars, rounds or wafers of a known fineness and weight.

Bullion Coin - A legal tender or numismatic coin with a market price dependent upon precious metal content as opposed to a face value. Examples include Australian Koalas, Canadian Maple Leafs, U.S. Gold and Silver Eagles, South African Kreugerrands, Viennese Philharmonics,

Bourse - A trading platform or market for buying and selling goods; typically refers to financial equities such as stocks or bonds trading, for example, on the New York Stock Exchange.

Bn - Brown, used for grading copper coins.

Body Bag - The term for a coin that the major grading services will not grade due to damage, altered surfaces or questionable authenticity. Since the coin is returned in a plastic bag, rather than a slab, the slang 'body bag' developed. 


Border - The raised circumference that forms the rim of a coin.


Brass - A metal alloy composed of copper and zinc.

Breakout - The removal of a coin from a certified slab and re-submittal to the same or other third party grading service with the intent to receive a higher grade.


Breen, Walter - Major numismatic author and historian.


Breen and Gillio Number - Nomenclature used to denote California territorial and private mint gold varieties.


Brick - 1) Slang for a bar of bullion. 2) A group of 4,000 Federal Reserve Notes; called a brick because of the metal strap binding.  3) 500 American silver Eagles sent from the U.S. Mint.


Brilliant - Having an coin surface appearance exactly as the day it was minted with no coloration or oxidation or blemish.


Brilliant Uncirculated - Coin Grade for coins that have not circulated and have no major blemishes (typically MS 62-MS63 Grades)


Broadstrike - A coin struck outside the restraining collar. 


Brockage - Error coin; a blank struck while another coin is still on the die, resulting in a ghosted image on the new coin.


Bronze - An alloy made of copper and tin.


Bronze Disease - A type of corrosion that attacks bronze and copper coins, typically ancients.


Brown - The color grade used for uncirculated and slabbed copper coins expressed as Brown (BN), Red-Brown (RB) or Red (RD).


Browning Number - Nomenclature for Bust Quarters die variety.


Brushed - A coin that has been 'gone over' with an abrasive brush.


Burnished - Term describes a coin that has gone under the buffing wheel.  Proof coins result in a glossy surface when the blank in burnished. 

Business Strike – Coin designed for circulation as currency.

Bust - A coin with a portrait of an individual shown from the shoulders up.



Cabinet Friction - Surface wear on a coin caused by friction with the container (tray, envelope) where it was stored.  Since many coins used to be stored in cabinets during the early days of coin colleting, this terminology stuck.

Cameo - A proof coin struck with brilliant watery or mirror like fields and devices of high contrast and precision.

Carat - This is a measurement of weight used in gemology.  It equals roughly 3.086 grains Troy or 0.2 grams.  NOTE: This Carat (starts with the letter 'c') is not the same as Karat (starts with the letter 'k') which is a measurement gold fineness.

Carbon-in-leach (CIL) process - A modification of the CIP process whereby carbon is added directly into the slurry during leaching as opposed to CIP where carbon is added after leaching is complete

Carbon-in-pulp (CIP) process - A process used to recover dissolved gold from a cyanide leach slurry. Coarse activated carbon particles are moved counter-current to the slurry, absorbing the gold as it passes through the circuit. Loaded carbon is removed from the slurry by screening. The gold is recovered from the loaded carbon by stripping in a caustic cyanide solution followed by electrolysis or by zinc precipitation.

Carbon Spot - A dark, typically black, discoloration on a blank that also transfers to the struck coin.

Carson City - A coin mint mark representing a former US Mint in northern Nevada.  Now defunct, the mint produced gold and silver coins between 1870-93.

Cartwheel - The term describing the play of light across a silver coin which displays the effect of light caught within field striations as one rotates the coin.  Enhances eye appeal.

Cash-cost - A measure of the average cost of producing an ounce of gold, calculated by dividing the total working costs (excluding corporate administration) in a period by the total gold production over the same period. Working costs represent total operating costs less royalties and depreciation. In determining the cash-cost of different elements of the operations, production overheads are allocated on a pro-rata basis.

Cast - A mould formed by pouring molten metal into a pre-formed shape. 

Cation - Chemistry, the negative anode.

cm - countermark. 

Check Mark - On the obverse of modern paper money, the letter/number combination in lower right corner of the note.

Chopmark - In the 1800's, especially in S.E. Asia or 'China Towns' in the US, merchants would strike a coin with a punch in an attempt to determine authenticity of the coin - leaving a character on the surface of the coin (especially Trade Dollars) from the punch.

Chicago Board of Trade (CBOT) - A commodity bourse.

Certified - A coin or other collectible that has been authenticated and verified by a third party assessor.

Charlotte - (C) a mint mark representing the former North Carolina mint that produced gold coins between 1838-61.

Choice Gem - A high quality coin in state MS 65+.

Chop Mark - A punched impression in a coin (especially Trade Dollars), typically those circulated in China, to determine metallic content and genuiness of a coin.

Clash mark - Markings on a coin such as a trace outline or remnants of devices from the opposite side of the coin that appear due to dies 'clashing' - striking together without a flan in between and subsequently transferring a small part of the design onto the opposing die.

Clip - A coin with an irregular (incomplete) planchet.

Cohen number - established in 1982 to represent Die Varieties for Half Cents produced between 1793-1857.

Colonial - Coins issued by the Colonial governments of British Colonies before they became States.

Circulated - A coin or paper money that has been handled as part of daily commerce and hence is not longer in mint state.

Coin - Unit of the realm.

Collar- The metal ring on a coin die which serves as the edge design of the piece being struck.

Comminution - Mechanical shredding or pulverizing of ore or waste material.

Commemorative -  A coin or other collectible produced not to serve as circulation currency, but to mark the passing of a n event or the significance of a person or place.

Compound-interest Treasury note - U.S. paper money issued in 1863 and 1864. Congress intended that these notes, bearing 6 percent interest, only circulate three years before redemption. However they stayed in circulation until the early 1900s.

Concentrate - Material that has been processed to increase the content of the contained metal or mineral relative to the contained waste.

Concordance – A numismatic reference material.

Condition - A rated scale of appearance and quality. See Grading.

Condition census - The calculation of the finest known and other top specimens of any given coin series.

Contact Mark - See "Bag Mark".

Coronet - A type of Liberty Head design on U.S. copper and gold coins in the 19th century.

Corrosion – This is a chemical reaction degrading the appearance or integrity of a metal.  Corrosion changes either the nature of the metal or results in a loss of metal to the process.

Counterfeit - A fake or imitation coin or other item produced to deceive through similarity in appearance with the original model.

Counterstamp - A coin that has an engraving, typically initials, that was imprinted or engraved after leaving the mint.

Crack out – Term when an individual breaks out a coin from a slab to re-submit the coin, hoping for a higher grade.

Craton - immobile slice of the earth's crust.

Cross section - A diagrammatic drawing that shows features that are transected by a vertical plane which is drawn at right angles to the primary geologic factor displayed along a longer axis.

Crosscut - A mine working which is driven horizontally and at right angles to an adit, drift or level.

Crossover - Term when an individual submits a coin in a slab to a competing grading service, hoping for a higher grade.

Crown - A term covering any generic coin with a weight between 20 to 30 grams and size less than 45mm.

Cu - copper

Cud - An out of place piece of metal that has attached to the planchet or been stamped on the coin which is not part of the design.

Cull - A coin or other worn or damaged to the point there is not value other than intrinsic.

Cupro-Nickel.  A coin combining more copper than nickel. e.g. Cupro-Nickel alloy, Cupro-nickel Composition.

Currency - Circulating medium of exchange for goods and services; legal tender.

Cut-off grade - The lowest grade of the mineralized material considered economic to extract; used in the calculation of the ore reserves in a given deposit.

Cyanide leaching - The extraction of a precious metal from an ore by its dissolution in a cyanide solution.



Dahlonega - A former US mint in Georgia, with Mint mark (D) that produced gold coins between 1838-61. 

Date Back - Bank note issues by the Second National bank between 1902-1908 (dates are on the back of the note).

Debase - To make or become worth less through removal of intrinsic value.

Decline shaft - An inclined shaft

Deep Cameo - A proof coin with very high grade and mirror-like surfaces; also a coin grade. 

Deep Mirror -  Cameo appearance of a coin; mirror or watery-like deep finish that adds a premium to a coin's value.

Deep Mirror Proof Like -  A business-struck mint coin with a cameo appearance of a coin having mirror or watery-like deep finish that looks like the coin was proof-struck, adding a visual and collectible premium.

Demand Note - US federal paper issued for circulation in 1861. AKA 'greenback' based on note design.

Denarius - Roman coin; first silver and later debased.

Denomination - Face value on coin and currency; the amount the money commands in trade.

Denticles - The 'teeth' on the outside collar/rim of the coin. Aka 'beading'.

Denver - A US mint in Colorado, using mint mark (D) that has produced US coinage since 1906.

Device – The primary coin design(s).  The bland areas surrounding the device is called the field.

Diamond drilling (core drilling) - A drilling method whereby the rock is cut with a diamond bit, usually to extract cores.

Die(s) - Two metal cylinders strike each side of a blank coin planchet to impress the device into a blank planchet, making the coin.

Die Clash - When two dies strike without a planchet in between, each die leaves an impression onto the other. Following the clash, coins struck from these same dies will show traces of the opposing design.  That is, the obverse will show hints of the reverse design.  The dies must be polished or replaced; the clash will eventually fade with die wear.

Die crack(s) – A damaged die upon striking the planchetwill leave a particular type of minor flaw, called a diagnostic, on the coin. With a crack, there is a space called a recess on the striking die.  Therefore the strike will cause metal to melt and flow through the recess and leave a small error in relief.

Die Trial – Use of a different metal other than the one used in the business strike, either on purpose or by accident.

Die Wear – Dies wear out after use and are resurfaced to remove problems and revive the hub. Without proper sanding and finishing, (or with rust or corrosion) worn dies will produce very small lines on the face of the die, resulting in minor scratching upon the struck coin.  Eventually the worn die will produce less detail in the fine dies, resulting in coins with apparent weak strikes.

Dilution - Waste which is commingled with ore in the mining process

Dip - The angle that a structural surface, such as a fault plane, makes with the horizontal axis as measured perpendicular to the structure strike.

Dipped - A coin that has had artificial chemicals applied to lighten or whiten the coin.

Disme - How "dime" was spelled per authorization of the 10-cent coin by the Mint Act of April 2, 1792

Doré - Unrefined alloy consisting predominantly of gold with lesser quantities of silver and base metals.

Double denomination - A type of coin minting error where a coin is re-struck by the die of a separate and different denomination (face value).

Double die - A coin that has a doubled image created by a die that had a multiple image.

Doubled Die Reverse - A coin variety with a doubled image on the reverse created by a die with a double image.

Double Eagle - US $20 gold coin.

Doubloon - Slang for the Spanish gold 8-escudo gold pieces, Conquistador Era.

Drachm - Greek silver coin.

Drift/drive - A horizontal tunnel driven along, or parallel to, the strike of the orebody, for the extraction or exploration of ore.

Ducat - A gold coin from the medieval age.


Eagle - $10 dollar US gold coin

EDS - Energy Dispersive Spectroscopy is a type of micro metal analysis.

Edge - The perimeter third side of a coin.  The plane where two facets of a stone meet.

Educational notes - $1, $2 and $5 silver certificates are printed from 1896 to 1899.

Electrotype - A counterfeit or copy coin developed by use of electroplating an impression, typically using wax, of the counterfeited coin. 

Electrum - This naturally occurring gold/silver alloy was used for coinage in early Mediterranean civilizations.

Encapsulated coin - That which has been placed, certified, authenticated, graded and sealed in a plastic holder by a third-party grading service.

Environmental Damage - Damage to the surface of a coin caused by improper yet unknown storage; this will prevent a coin from being assigned a grade by a third-party grading service.

Error -  A mistake in the design or production of  a coin, or reference to the coin itself.

Essai/essay  - A test print to check design on paper money.

Exergue - The portion of a coin containing mint mark and date.

Exonumia - Token, medallions, or other types of objects similar to coins holding a monetary value but not serving as currency.

Eye appeal – A subjective visual quality than enhance the appearance of a coin.


Face, Face Value - The currency value that is marked on a coin.

Fantasy - An object similar to the coin made by private concerns for their own use and enjoyment, not for circulation as currency.

Fault  - Displacement along a surface fracture or zone.

Fe - Iron

Feasibility Study - The definitive engineering and economic study that determines the economic viability of a mineral deposit.

Field –Those blank coin surfaces surrounding the coins devices.  Collectors like finely polished fields enumerated as proof like, deep proof like, or cameo.

Face - AKA Obverse; the front of the coin or currency.  Name generated because the obverse often has the face of a person on the coin.

Facet - Cut or face of a gemstone; the cleavage plane of a particular crystalline form.

Face Value - The denomination of coin or currency (One dollar, Ten Cents, etc.)

Fine/Fine Gold/fineness - Only refers to pure Au at 24 Karat - .999 fine - gold.  Fineness is a description of gold purity presented in parts per thousand where .999 means only one out of a thousand parts is a non-gold substance (likely copper or silver or other elements commonly found in ore with gold).

Flan -See planchet.  AKA blank.

Flotation - A recovery process by which valuable minerals are separated from waste to produce a concentrate. Selected minerals are induced to become attached to air bubbles and to float.

Flowline - hairlines in the field of a coin formed when pressure of the dies striking the flan caused the metal to molt (turn liquid) and flow radially away from the center of the strike.

Fold - A curve or bend in planar structures such as rock strata or  bedding planes.

Follis - A Roman or Byzantine coin denomination.

Footwall - The underlying side of a fault, an orebody, or mine workings

Formation - A distinct layer of similarly composed sedimentary rock.

Forward sales - The sale of a commodity for delivery at a specified future date and price, usually at a premium to the spot price.

FPL - Fixed Price List.  This is an inventory with the ask price.

Fractional - In coinage, those less than face value of one dollar. In currency, those paper notes produced between 1862 and 1876 with denominations ranging from 3 to 50 cents.

Frequently Asked Question - (FAQ) Internet phrase; list of common questions and answers.

Frost - A description with proof coins describing that look caused sandblasted dies striking the planchet to make the coin.

Full Step - A Jefferson Nickel with a fully struck obverse.

Full Split Bands - A Mercury Dime with a fully struck obverse.

Full Head - A Standing Liberty Quarter with a fully struck obverse.

Full Strike – Excellent detail in the coin devices.




Gallery Mint Museum - A private mint that produces replicas/copies of early US coins.


Gem Uncirculated - An uncirculated coin in MS 65 or higher.


Geochemistry - The study of the distribution and amounts of the chemical elements in the media (air, sediment, soil and water).


Geochemical Prospecting -  A prospecting technique where the content of certain metals in soil and ore defines anomalies that are further tested.


Geochemical sampling - Samples of soils, stream sediments or rock chips taken to ensure the quantities of trace and minor elements.


Geophysics - The study of the mechanical and physical properties of the earth’s crust.


Geophysical Surveys - An exploratory methodology used to determine buried physical and geomorphic structures at the earth’s surface.


Glue Residue - The remnants of improper glue use on a coin - this will prevent a coin from being assigned a grade by a third-party grading service.

Gold - A precious metal.


Goldine - A quasi gold-colored finish used on base metal tokens and medallions.


Goldline International - Precious metal dealer.

Grade - 1. The relative quality or percentage of ore metal content. 2. That subjective opinion assigned to a coin or other tangible asset by a third party.

Graffiti - A coin that had initials or figures inscribed into the surface after leaving the mint.

Grain - An early weight derived from one grain or wheat or barley.  Today a grain is recognized as 0.0648 grams troy. See Weights and Measures for more information.

Gram - A metric unit of both mass and weight. A gram used in troy weight to measure gold is approximately 1/32 troy ounce.  See Weights and Measures for more information.

Graphitic Phyllite - A low-grade metamorphic rock composed of graphitic carbon.

Greenstone - A sequence of metamorphosed volcanic sedimentary rock assemblages

Greysheet - Name for the Coin Dealer Newsletter - a pricing guide for coin purchases between dealers.


Hairlines- Light surface scratches on a coin.

Half Eagle - A US 5-dollar gold coin.

Hammer (die) - That die which strikes the planchet, forming the coin. AKA 'anvil die'.

Hanging Wall - Geological term referring to the rock above a fault or vein, or overlying a natural feature (as opposed to footwall).

Hard Times Token - An unofficial large copper token typically made between 1833-1843 which served as de facto currency due to coin shortage.

Heap leaching - A low-cost technique for extracting metals from ore by percolating leaching solutions through heaps of ore placed on impervious pads. Generally used on low-grade ores.

Highwall - A subterranean lode or seam exposed via large cut made by machinery. Also refers to the type of mining that uses equipment to remove aggregate from the lode exposed by the cut. [mining].

Hoard - A collection of coins that had been lost to the vagaries of time, only to be accidentally discovered by someone else at a later date. AKA 'Treasure'.

Hobo or Love Token: A worn coin such as a buffalo nickel upon which an artisan has inscribed an image or pattern. These gained their name based on the the original artisans, those drifting hobos riding the rail system during the depression and spending their riding hours inscribing fanciful or devotional patterns into what little coinage they held.

Hologram - Any three-dimensional image projected upon a flat surface especially as a security device on paper or plastic currency.

Host rock - The rock containing a mineral or ore body

Hub – A mirror image of a relief die used to make exact replica working dies.

Hydrothermal -  The action or process of water heater deep within the earth such as hotsprings, vents, mudpots, fumaroles, precipitated travertine, and geysers.



Igneous - Rock formed by the solidification of mineral-rich molten lava either erupted or intruded into bedrock. 
from a volcano.


Impaired - The term used to describe a Proof coin that has had its surface marred somehow.


Inaugural medal - Those medal issued by inaugural committee upon inauguration of a new US president


Incuse - The recessed (rather than raised) design used on coinage, or exonumia. The US 2.5 gold eagle serves a great example. (opposite of bas--relief).


Ingot - A shaped form, such as a bar, of precious metals that bears the fineness and weight of metal, and typically an assay or producer marking.


Inscription - The motto across the reverse and wording across the obverse of a coin, currency or exonumia.  AKA legend.

Intaglio - The method for printing paper, especially currency, using engraved plates. The paper is machine fed into the plate lines which are filled with ink. This produces a raised line of print on the paper. 


Intrinsic Value – The financial value of the amount of metal in a coin and the seignorage of the coin. AKA melt value.


Irradiated dime - Those Roosevelt dimes produced by exposing the coin radioactive materials, typically cesium. The coin was then marketed and sold to the same dupes who thought FD Roosevelt served his country with anything resembling honor.




Jeton - Coin like metal disc used by merchants to mark account status.


John Reich number - Nomenclature used for Bust Dime varieties between 1794-1837.


JORC - Joint Ore Reserves Committee. An Australian committee responsible for promulgating the Australasian Code for Reporting of Mineral

Resources and Ore Reserves.


Judd number - Nomenclature used for varieties of pattern or experimental coins.


Jugate - co-joined coinage or exonumia.




Kriging - A method of block grade interpolation which takes into account characteristics of ore mineralization.

Krugerrand - A South African gold bullion coin (.9167 fine) available as full ounce or fractional ounce.



Lamination - A clad or plated coin defect typically called a peel where the metal separates from the surface due to alloy impurities, dirty planchet, or other planchet stresses.

Large Cent - American coinage produced between 1793 and 1857.

Large date - A coin variety where the date is larger than the more common strike for the year. 

Lacquered - A coin that had clear lacquer placed on the surface to prevent toning (commonly done years ago) will will prevent a coin from being assigned a grade by a third-party grading service.

LE – Lettered edge.

Legal Tender - The payment for debt per legislation; fulfills the obligation of payment between the bearer and the borrower.

Legend - The motto on the reverse of a coin, currency or exonumia.

Lepton - Small Greek coin, both ancient and modern, typically brass or bronze.

Lettered Edge - The third side of the coin with script, either incuse or raised.

Libertad - Mexico gold bullion one-ounce .999 fine silver coin.

Life of Mine - The term referring to all aspects of a mining project necessary to extract all known reserves.

Lignadenarist - Wooden nickel and token collector. 

Lint mark - A small mark caused on a coin following polishing which left a thread on the die surface.

Liquidity - The quality of easily conversion into other stores of value or currency.  The depth of a commodity or financial vehicle.  For example, a stock that trades only 1,000 for day is not nearly as liquid as a stock that trades 1,000,000 per day.  A low liquidity often causes wider spreads between buy and ask prices.

Lithology - The physical appearance and characteristic of a rock or body.

Logan-McCloskey number - Nomenclature for Bust Half Dime varieties produced between 1792-1837.

Loupe - A magnifying glass used by jewelers, geologists, and numismatists.

Love token - Coins that have been altered by individuals who smooth the coin surface and and engrave their own design.

Luster - The coin surface appeal that represents the original skin still left which has not been altered. The luster appears as a watery flow which actually reflects light scattered along flow lines.


Maple Leaf - Canadian bullion coin made of .9999 fine gold available in one-ounce and fractional amounts.

Maria Theresia Taler - An Austrian silver trade coin which is always dated 1780 despite actual year produced.

Market Value - The price a coin will bring in the open retail market; the price the crowd may bear.

Master hub/die - A the metal punch used to produce a working hubs which in turn produces working dies used to strike planchets into coins.

Matte Proof - U.S. proof modern coins and gold coins of 1908-1916 produced from sandblasted or burnished dies.

Maverick - A token that cannot be identified, authenticated or defined.

Medal - A token like object not used for legal tender exchange or purchase of goods or services as with a token, but instead used to confer some non-monetary rights or privilege. Typically has either a design or motto.

Medalet/Medallion - Medals of varying size.

Microprinting - Very small lettering used on paper currency to discourage counterfeiting.

Milling/mill - The comminution of the ore, although the term has come to cover the broad range of machinery inside the treatment plant where gold is separated from the ore.

Milled Edge - The surface of the coin band that is either reeded or contains lettering.

ME – Millennium Edition. A limited production run of coins and other collectors items to commemorate the year 2000.

Medal - A token like object not used for legal tender exchange or purchase of goods or services as with a token, but instead used to confer some non-monetary rights or privilege. Typically has either a design or motto.

Metamorphic - Sedimentary and igneous rocks which have been altered in composition, structure or  texture by processes involving pressure, heat and
the introduction of new chemicals.

Metasediment - Sedimentary rock showing evidence of metamorphism.

Metavolcanic - Volcanic rock which shows evidence of  metamorphism.

Mine call factor - The ratio of the grade of material received at the mill to the grade of ore calculated by sampling in stopes.

Mine Plan of Operation -

Mineral - A naturally occurring inorganic crystalline material with a known and definite chemical composition

Mineralization - Natural accumulation or concentration in potentially economic minerals; and the process producing such.

Mineralogy - The science of the origin and use of minerals.

Mineral resources - [Also see Mining]

Measured mineral resources have been calculated for tonnage or volume from dimensions revealed in outcrops, pits, trenches, drill holes, or mine workings, and supported by other appropriate exploration techniques. The sites used for inspection sampling and measuring must be so spaced that the geological character, continuity, grades, and nature of the material are so well defined that the physical character, size, shape, quality and mineral content can be established with a high degree of certainty.

Indicated mineral resources is that portion of a mineral resource for which quantity and quality can only be estimated with a lower degree of certainty than for a measured mineral resource. The sites used for inspection, sampling and measurement are too widely or inappropriately spaced to enable the mineral or its continuity to be defined or its grade throughout to be established.

Mineralized Zone - Any mass of rock in which minerals, at least one of which has commercial value, occur.

Minor coin - Any base metal coin or silver coin less than crown weight.

 Mint - A private or governmental concern that manufactures coins, medallions, or tokens. Also used to refer to 'mint state'.

Mintmark - The letter or other symbol provided on either the obverse or reverse used to denote the mint which produced the coin. 

Mint Set - A group or set of coins which are produced by a mint consisting of each denomination made during the particular production run year.  

Mint State - The term that describes an object that shows no wear or damage from circulation. That is, the coin is in the same state as the day it left the mint. AKA Gem Uncirculated.  

Mintage - The quantity of each coin produced by the mint during the production year. 

Mirror - A highly reflective and watery surface - especially the field -of a coin.  These coins are sought by collectors and therefore carry a premium. Grading services use the terms 'deep mirror' and 'proof like deep mirror' to confer on especially beautiful coins.

Misch -  A combination of rare-earth minerals.

Model - A three-dimensional mock up of a coin design made out of clay or plaster used to produce working dies and hubs.

Motto - AKA legend. A phrase appearing on the reverse of a coin e.g. "In God We Trust".

Mud Rotary - A drilling method using a sleeve in heaving sands to prevent slippage.

Mule – An error produced either by using dissimilar dies (two heads) or a coin struck in either the wrong planchet or metal.

Mylar -


Numismatic Literary Guild - Association of numismatic authors and related material.

New Orleans (Louisiana) - US Mint that produced coinage between 1838-1861 and then again between1879-1909.

Newcomb number - Nomenclature for die varieties in US Large Cents produced between 1816-1868.

Numismatic Guarantee Corporation of America -

Ni - Nickel metal. In numismatic terminology may refer to cupro-nickel.  See

Non-circulating legal tender coin - a coin such as the one-ounce US Gold American Eagle with a legal tender (face) value of $50 but an intrinsic value several fold.

Non-refractory - Ore containing gold that can be satisfactorily recovered by standard mining techniques such as basic gravity concentration or simple cyanidation.

Notgeld - The term for Weimar Germany hyper-inflated notes

Novodel – Coin struck with a backdated die. 

Numismatics - The collecting, research, and study of coins and currency such as medals, paper money, tokens and similar.

NYMEX -New York Mercantile Exchange. A commodity bourse in New York City. 


Open pit/open cut - Surface mining in which the ore is extracted from a pit.

Ore - Material that contains one or more minerals, at least one of which has commercial value and which can be recovered at a profit.


Orebody - A continuous well defined mass of material of sufficient ore content to make extraction economically feasible.


Ore grade - The average weight of the recoverable mineral expressed as a specific weight.

Original - Having  undamaged or non-modified surface where the coin is in a natural state.  The coin may be either brilliant or toned (surface color patina) but cannot have been cleaned or chemically altered.


Oxide - The portion of a mineral deposit within which sulphide materials have been oxidised, usually by surface weathering processes.


Ounce - A liquid and dry weight.  Equal to 1/16 avoirdupois pound or 1/12 troy pound.


Outcrop - A geologic formation or structure appearing at the earth's surface.


Over Mint Mark - On a coin a die variety where two different mintmarks were used by on one die.  involved.

Overton Number -  Nomenclature for Bust Half Dollar varieties


Patina - AKA toning. Surfaces naturally altered by the effect of time and oxidation to provide color or finish.

Pattern – Sample coin design not intended for business strike.

Pb -Lead

Pre-feasibility study - That stage where determining factors of economic viability such as engineering achievements and costs is at the ± 25% stage.

Proterozoic - The time division of the Precambrian between 2,500 million and 550 million years ago.

Professional Coin Grading Service (PCGS) -

P.E. - plain edge.

Pedigree – A coin’s lineage and numismatic history.

Pitted - The existence of a poor surface due to corrosion or other environmental factors.

Planchet – Metal slug struck by a die to produce a coin.  AKA blank, flan.

Planchet flaw - Any problem such as a clip, lamination peel (metal separation) or other problem that appeared before or during striking of the coin before leaving the mint.

Planchet striations - Hairline scratches appearing on a coin’s surface caused by heavy planchet polish.  Alternately, when a planchet is polished the hairline flows seem to appear ‘above’ the surface of the coin.

Plunge - The angle from the horizontal of the linear geological feature along a plane.

Polished - A coin that has had an abrasive brush or wheel applied to alter it's appearance.

Poly Vinyl Chloride - An ingredient in a type of soft plastic often used in "flips" or insert type coin holder.  PVC will damage coins given enough contact time, depositing an ugly green slime or spots. Acetone will often remove this PVC residue. 

Poor - (Pr) Coin grade, basal state - lowest grade possible.

Porous - The existence of a grainy or pitted surface due to chemical oxidation.  Typically on copper coinage.

Prestige Set - A set coins made by the US mint that has both the proof versions of the years production run and any proof commemorative issues produced by the mint that year.

PR: Proof; proof strike -  Designed for collectors, not for circulation.  A proof coin is produced by techniques different than those for normally circulating, or business strikes, and utilize dies and planchets specifically prepared to withstand higher pressure or multiple striking.  These techniques result in a coin exhibiting a sharpness of detail and devices against almost flawless watery or mirror-like fields that command a premium from the numismatic community.

Premium - The difference between the intrinsic and market value. For example, a silver coin with $5 worth of silver by weight which trades for $20 on the open market has a %400 premium built in.

Pre-stripping - Removal of overburden in advance of beginning operations to remove ore in an open pit operation.

Professional Numismatists Guild - Organization of professional coin dealers, enthusiasts, and numismatists.

Prospect - A mineral deposit with insufficient data available on mineralization to determine if it is economically recoverable, but warranting further investigation.

Prospecting license - An area for which permission to explore has been granted.

Proof Like - A business strike coin with such an exceptional appearance that it approaches the quality and beauty of a proof strike coin.

PVC – Poly Vinyl Chloride, a plastic used to provide protection to coins from environmental conditions. Over time the PVC accreted onto the surface of a coin. If caught in time, it may be removed by (very careful!) application of acetone.

Pyrite - Iron sulfide


Quartz - A mineral compound of silicon and oxygen; may transparent to white-coloured.


Rarity Scale - A coin rarity index ranging from (R1) most common to (R8) most rare. 

Rattler - Coin that is loose within a slab to the point where it can rotate within the holder.

Raw – A coin that is not received grading and encapsulation by a third party grading service.

RB - Red-brown.  A grading criterion for copper coins.

Rd – Red.  A grading criterion for copper coins.  Typically a Red coin will be valued at a premium to Red-brown or Brown coins.

R.E. - Reeded edge around the coin outer band.

Reef  - A tabular ore body.

Refining - The final stage of metal production in which remaining impurities are removed from the molten material by introducing air and fluxes. The impurities are removed as gases or as slag.

Refractory ore - Any ore that does not respond to conventional mineral processing (cyanidation) to produce acceptable product recoveries without an intermediate step to address its refractory attributes (usually some form of oxidation).

Relief - Coin surface design devices that are raised from the field to produce a depth effect.


Proven reserves - Those measured mineral resources of which detailed technical and economic studies have demonstrated that extraction can be justified at the time of determination and under specific conditions.

Probable reserves - Those measured and/or indicated mineral resources which are not yet "proven" but of which detailed technical and economic studies have demonstrated that extraction can be justified at the time of determination and under specific conditions.

Residue - The condition on a coin used by third party graders to indicate some unspecified 'gunk' on the surface of a coin that precludes grading of the coin by the certification company.

Restrike- A coin struck from the Mint after the initial production run.

Reverse circulation drilling - A drilling method employing double walled drill rods. The drilling fluid (usually water) is pushed down the shaft around the rods and the cuttings are blown up the middle.

Rim - The outer most coin surface; perpendicular to the edge.

Rotary air blast - A relatively inexpensive and quick exploration drilling method returning rock chips to the surface using high air pressure.

Round - A bullion with similar appearance or size to a large dollar coin, but with no monetary or tender value other than the content of the metal.

Run-of-mine - The quality (tonnage, grade) of ore delivered at the processing plant


Sampling - Taking small pieces of rock at intervals along exposed mineralisation to determine mineral content.

San Francisco - US Mint in California and associated mintmark (S) used between 1854-1955.

Scratch – A mark left on a coin during circulation, detracting from the appeal and value of the coin.  Different than flow lines or striations caused during striking the coin.

Scrip - Any paper note or bill issued by and good for purchase at a private enterprise or group of enterprises. 

Sediment - Particles transported by gravity (colluvium), water (alluvium), wind (aeolian) or ice.

Sedimentary -  The rock or process of rock formed at the earth’s surface from either mineral or organic particles that have been re-deposited from their area of origin.

Seigniorage - The difference between what the face value of a coin is, and the net cost to produce and deliver that same coin into circulation.


Series - Currency or coins of the same major design.  Also refers to the entire production run of dates and mintmarks e.g. the mercury dimes between 1916 and 1945 from the Philadelphia, Denver, and San Francisco mints. Also refers to a run of currency notes with consecutive serial numbers.

Shaft - A mine-working (usually vertical) used to transport miners, supplies or equipment.

Shear -  A type of stress strain causing bodies of rock to
slide relative to each other in a direction parallel to their contact plane.

Shekel - A biblical metal coin circulating as currency.

Sheldon Number - Variety nomenclature for Large Cents

Sheldon Scale of Grading - A numerical and empirical grading system, between 1-70, that provides relative scores to the numismatic value of a coin.  Between the grades of 4 and 60 the even numbers only are used.  That is, a very strong About Uncirculated coin would grade AU+ instead of AU 59.

Poor : 1

Fair : 2

About Good :  3

Good : 4-9

Very Good: 10-11

Fine: 12-18

Very Fine: 20-35

Extra Fine 40-45

About Uncirculated: 50-59

Uncirculated: 60-62

Choice Uncirculated: 63-64


Shield - A large area of exposed basement rocks surrounded by an assemblage of younger rocks.

Silver Certificate - Paper currency produced by the government with a promissory backing of face value silver. 

Silver Clad - A coin with a clad core and a thin silver veneer e.g. 1965 Kennedy Half Dollar.

Silver Eagle - The one-ounce silver coin produced by the US mint staring in 1986 with a 1$ face value.


Strike – The act of impression left by the dies hitting the planchets with force.  The type and quality of impression: business strike, proof, re-strike.  The qualities of  force , pressure and angle of a die striking a planchet.  Factors affecting strike include: Angle of die strike; planchet quality and properties such as uniformity or relative hardness; die condition; quality of dies and hubs; and heat of the planchet at moment of strike.


Si - Silicon, an element.

Sintered (Planchet) - A coin blank (planchet) which stuck in the annealing drum and was subsequently heated but not enough to melt metal that stuck onto the planchet in the annealing drum.

Slab – The term used describe a con professionally graded and encapsulated. Coins are encapsulated in plastic, such as Poly Vinyl Chloride, to certify the grading company and protect the coin from environmental conditions. 

Smoothing - Similar to tooling, when a coin's fields are artificially changed via unknown methods or tools to hide damage or corrosion or remove scratches.

Sn - Tin, a base metal.  

Soft strike –Also known as a ‘weak’ strike.  A coin produced with weak or flat devices and features.  Cased by old dies or reduced pressure during striking to preserve die life. 

Splasher – Term used to describe uniface die or hub trial runs.

Specific gravity - The ratio of the weight of a known volume of a substance to the weight of an equal volume of some reference substance (typically water or mercury). 

Also, the ratio of the masses of equal volumes of each substance:

Aluminum 2.6989,

Bismuth 9.75,

Chromium 7.2,

Cesium 1.873 (softest metal)

Copper 8.96,

Gold 19.32

Iron 7.87

Lead 11.35

Magnesium 1.738

Manganese 7.2 to 7.45

Nickel 8.902,

Palladium 12.02

Platinum 21.45

Silicon 2.33

Silver 10.50

Tin (gray) 5.75, Tin (white) 7.30

Titanium 4.54

Tungsten 19.30

Zinc 7.133.

Specimen - A specially minted coins of extremely high quality manufacture. Typically includes specially prepared planchets and a proof like appearance. 

Spot - A flyspeck, especially of carbon on silver or copper flecks on gold coins.

Spot Price - aka cash price.  The current market price for immediate delivery of a physical metal or coin.

Spread - The difference between buy and ask prices serving as the profit maker or hedge against market fluctuations; aka vigorish.

Stain - Discoloration, but not corrosion, on a coin that prevents coin grading by a third party grading firm.

Stope - The underground excavation, especially a vertical-trending bore, from which ore is extracted.

Stratigraphic - Geology explaining the origin and succession of strata.

Strike - the direction or trend that a structural surface, e.g. a bedding or fault plane, takes as it intersects the horizontal

Strike length - The horizontal distance along the direction that a structural surface takes as it intersects the horizontal.

Stripping - The process of removing overburden to expose ore.

Stripping ratio - The ratio of overburden and segregable waste to ore in an open pit operation.

Sulphide - A mineral characterized by the linkages of sulfur with a metal or semi-metal, iron sulphide. Also a zone in which sulphide minerals occur

Surface Hairline - Abrasive if faint lines that occurred from rubbing a coin with a cloth.

Syncline - A concave downward fold, with stratigraphically younger rock in the core.

Synform - A formation bent or downward folded.



Tailings - The waste material from ore after the economically recoverable metals and minerals have been extracted. Changes in the metal prices and improvements in technology can sometimes make the tailings economic to reprocess at a later stage.

Tailings Pond - A constructed settling basin for waste material.

Talent - A biblical weight referring to precious metal. Approximately the size of a cannonball according.

Third Party Grading (TPG) -  An independent coin grading company that provides a coin grade and certification for a fee.

Thumbing - A technique of rubbing a finger and thumb across the coin to dull blemishes or scratches or clean the surface.

Token – A struck, stamped or printed planchet produced by a private mint used to purchase or exchange services.  For example, a bus or video game token.

Token coinage - A coin with an intrinsic value less than its face value.

Tonne - A metric tonne that equals 1,000 kilograms or 2,204.6 pounds.

Tooling - When a coin's fields are artificially changed using a power tools and as graver or polisher to hid damage or corrosion or remove scratches.

Total cash cost per ounce - The sum of total production costs (as reported on consolidated statement of operations) minus depreciation, depletion, amortization and asset retirement divided by number of ounces of gold sold during applicable period.

Trading Range - The average high and low prices of an investment.

Transition zone - A zone containing a mixture of oxide and sulphide material, usually lying between the oxide and sulphide zones.

Trenching - Making elongated open-air excavations for the purposes of mapping and sampling

Troy Ounce - A dry physical unit of weight for precious metals.  See Weights and Measures for more information.

TSP - Tri Sodium Phosphate.  A base used to clean coins.

Type Coin - Any individual coin of a design and denomination. 

Type Set
- A collection of each coin of of every design, denomination and mintmark.



Uncirculated - A coin that has not entered general commerce; a grade of MS60 or higher.

Uniface - A medal or token without a reverse pattern or motto.


Valentine number - Nomenclature for Half Dime varieties. 

Variety - A slight modification in devices or design within a particular coin series that provides a collectible reason to acquire such as die doubling or extra strike or metal that provides a unique coin or run of similar coins.

Variogram - A graphical representation of the rate of change of grade over a defined distance. Used to define parameters resource modelling.

Vein - a thin, sheet-like crosscutting body of a hydrothermal mineralization such as quartz.


Verdigris - Green rust on a copper surface. Copper acetates rather than surface carbonates.

Volcanics - Original fine grained molten rocks that have nearly reached the surface of the earth before solidifying.



Wall rock - Rock that is adjacent to vein weathering near surface alteration and mineral oxidation; rocks exposed to the atmosphere or ground water.

Waste - Rock lacking sufficient grade and/or other characteristics of ore to be commercially exploited.

Waste Heap - Synonym for tailings.

Wheel Marks - What is left when a coin counting machine leaves a rub mark, or a polished spot, on a coin.

White Metals - Platinum (Pt),  Palladium (Pd) and sometimes Silver (Ag) and Rh

Whizzing - The alteration of a coin surface through high speed polishing. Produces a surface artificially shiny with numerous hairlines.

Wiped - A coin that has surface hairlines from cleaning or mishandling.

Wire frame - A mesh system of triangles used in geologic computer models to define volume.

Wrappers – The paper outer paper shell container and any assorted documentation holding the coins in a roll. 


x-Ray Florescence – A mechanical analyses conducted to determine the presence or percentage of metal in an object.


Yield/recovered grade - The actual grade of ore realized after the mining and treatment process.




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