M - Coin Collecting Glossary

Keeping up with the Terms, Abbreviations and Jargon

can be sometimes frightening - We made is easier to understand

We hope that the following Coin Collecting Glossary on the most frequently used terms, acronyms, and definitions will be beneficial to you.

Coin Term Glossary
























Major Variety

A coin that is easily recognized as having a major difference from other coins of the same design, type, date, and mint.

Market Grading

A numerical grade that matches the grade at which a particular coin generally is traded in the marketplace. The grading standard used by PCGS.


Any imperfections acquired after the striking process.

Master Die

The main die produced from the master hub. Many working hubs are prepared from this single die.

Master hub

The original hub created by the portrait lathe. Master dies are created from this hub.

Matte Proof

An experimental Proof striking, produced by the U.S. Mint mainly from 1907 to 1916, which has sandblasted or acid-pickled surfaces.


Medium Date


A coin-like piece of metal made in honour of a person or event. Not authorized as legal tender nor intended to circulate. Not made to a recognized weight or fineness.


see Medal

Medal Press

A high-pressure coining press acquired by the U.S. Mint, circa 1854-1858, to strike medals, patterns, restrikes, and some regular-issue Proofs.

Medal Struck

The design of the obverse is of the same vertical axis as that of the reverse design.

Medium Date

A term referring to the size of the digits of the date on a coin. Use of this term implies that a large or small date exists for that coin or series.

Medium Letters

A term referring to the size of the lettering of the date on a coin. Use of this term implies that large or small letters exist for that coin or series.

Medium of Exchange

Money in any form when in actual use as a medium of exchange.


Jargon term for the intrinsic value of a particular numismatic item.

Mercury Dime

The common name for the Winged Liberty Head dime(1916 to 1945).

Metal Stress Lines

Radial lines, sometimes visible, that result when the metal flows outward from the centre of the planchet during the minting process.


Struck on planchets cut from rolled strips. Often wrongly used to denote the reeded edge of a coin.

Milling Mark

A mark that results when the reeded edge of one coin hits the surface of another coin. Such contact may produce just one mark or a group of staccato-like marks.

Minor Variety

A coin that has a minor difference from other coins of the same design, type, date, and mint. This minor difference is barely discernible to the unaided eye. The difference between a major variety and a minor variety is a matter of degree.


A coining facility that is registered and Government-owned. This facility is authorised by law and strictly audited and managed.

Mint Bloom

The Original lustre that is still noticeable on a coin.

Mint Luster

The dull, frosty, or satiny shine found on uncirculated coins.

Mint Mark

Variation of the mintmark. This is a letter or symbol of where the coin was minted.  Mint Marks is used for quality control and indicates where it was minted.

Mint Police

Special force or security team that protects all Mint buildings.

Mint Set

A set of Uncirculated coins from a particular year comprising coins. Each coin of the particular series is normally included in this set or available as single MS coins.

Mint Set Toning


This term refers to the colours and patterns coins have acquired from years of storage in the cardboard holders in which Mint Sets were issued from 1947-1958. Since 1959, Mint Sets have been issued in plastic sleeves, thus they do not tone as spectacularly.


Mint State

Mint State

The term corresponding to the numerical grades MS-60 through MS-70 used to denote a business strike coin that never has been in circulation.


The number of coins of a particular date struck at a given mint during a particular year.


The tiny letter(s) stamped into the dies to denote the mint at which a particular coin was struck.


A term applied to the error coins that have striking irregularities.

Mishandled Proof

A Proof coin that has been circulated, cleaned, or otherwise reduced to a level of preservation below PR-60.

Miss Liberty

The term applied to the various incarnations of the emblematic Liberty represented on United States coinage.

Missing Edge Lettering

Is a coin which does not display any of the intended design on the edge of the coin.


Medium Letters


see Mintmark


Jargon for an incredible coin, usually one that grades MS/PR-67 or higher. A secondary use is as an adjective, such as monster lustre or monster colour.


Jargon for an incredible coin, usually one that grades MS/PR-67 or higher.


Short for “Morgan dollar.”

Mottled Toning

Uneven toning, usually characterized by splotchy areas of drab colours.


An inscription or phrase on a coin. An example is a word EENDRAG MAAK MAGorUNITY IS STRENGTHon some South African coins. The Motto has a special meaning and can be emotional or inspiring.



This is for Mint State(the grade) and60(the numerical designation of that grade). This is the lowest of the eleven Mint State grades that range from MS60 through MS70. An MS60 coin will usually exhibit the maximum number of marks and/or hairlines. The lustre may range from poor to full but is usually on the poor side. Eye appeal is usually minimal.



This is for Mint State(the grade) and61(the numerical designation of that grade). This grade meets the minimum requirements of Mint State plus includes some virtues not found on MS60 coins. For instance, there may be slightly fewer marks than on an MS60 coin, or better lustre, or less negative eye appeal.


Mint State(the grade) and62(the numerical designation of that grade). This grade is nearly in the choice or MS63 category, but there is usually one thing that keeps it from a higher grade. Expect to find excessive marks or an extremely poor strike or dark and unattractive toning. Some MS62 coins will have clean surfaces and reasonably good eye appeal but exhibit many hairlines on the fields and devices.


Mint State(the grade) and 63(the numerical designation of that grade). The equivalent of choice or Choice BU from the days before numerical grading was prevalent. This grade is usually found with clean fields and distracting marks or hairlines on the devices OR clean devices with distracting marks or hairlines in the fields. The strike and lustre can range from average to excellent.



Mint State(the grade) and64(the numerical designation of that grade). This grade is also called Borderline Gemat times, as well as Very Choice BU. There will be no more than a couple of significant marks or, possibly, a number of light abrasions. The overall visual impact of the coin will be positive. The strike will range from average to full and the lustre breaks will be minimal.


Mint State(the grade) and65(the numerical designation of that grade). This grade is also calledGemorGem Mint StateorGem BU. There may be scattered marks, hairlines or other defects, but they will be minor. Any spots on copper coins will also be minor. The coin must be well struck with positive(average or better) eye appeal.


Mint State(the grade) and66(the numerical designation of that grade). This is not only a Gem-quality coin, but the eye appeal ranges from above average to superb. The lustre is usually far above average, and any toning can not impede the lustre in any significant way.



Mint State(the grade) and67(the numerical designation of that grade). A superb-quality coin! Any abrasions are extremely light and do not detract from the coin’s beauty in any way. The strike is extremely sharp (or full) and the lustre is outstanding.



Mint State(the grade) and68(the numerical designation of that grade). A nearly perfect coin, with only minuscule imperfections visible to the naked eye. The strike will be exceptionally sharp and the lustre will glow.



Mint State(the grade) and69(the numerical designation of that grade). Virtually perfect in all departments, including wondrous surfaces, a 99% full strike (or better), full unbroken booming lustre and show-stopping eye appeal. You may have to study this coin with a 5X glass to find the reason why it didn’t grade MS70.


The Perfect Coin


Mint State(the grade) and70(the numerical designation of that grade). A perfect coin! Even with 5X magnification, there are no marks, hairlines or lustre breaks in evidence. The lustre is vibrant, the strike is razor-sharp, and the eye appeal is the ultimate. Note: Minor die polish and light die breaks are not considered to be defects on circulation strike coins.

Mule Error

This is a rare Mint error when the obverse die is of one coin and the reverse die is of a different coin.

Examples of Mule errors: Sacagawea dollar/Washington quarter Mule, where a Washington quarter obverse is paired with a Sacagawea reverse.


Describe a coin that has been damaged and in such a bad state, that it can no longer be graded.

If we missed a word or phrase, please let us know. We would like to grow and expand this list with your help.