Letter M

Master Die

The die which is used to produce several hubs, which in turn are used to make many working dies. The master die is never used to strike coins. See Hub.

Malleable (in Plasticity)

An ability to change shape drastically without breaking

Maple Leaf:

See Canadian Maple Leaf (Gold or Silver).

Market Value

The price at which a coin or bullion item trades.


The premium assigned to an item in order to make a profit.

Matte Proof

A certain type of proof coin minted in the United States, mostly from 1908 to 1916. Matte proofs have a dull, granular finish without any mirrorlike qualities.


A metal round that looks like a coin but has no denomination and isn’t recognized as legal tender. Can be issued by both private and government mints.

Melt (Price)

Value determined by the current price without any fees added.

Melt Value

Value determined by the current price without any fees added.

Mercanti, John M

The 12th Chief Engraver of the United States Mint.

Metric Ton

1,000 kilograms or 32,151 troy oz.

Mexican 50 Peso

Often referred to as a “Centario”, these large gold coins are a tribute to Mexico’s independence from Spain in 1821.

Milling Mark

Also reeding mark. A series of two or more small nicks on a coin which result from contact with the reeded edge of another coin, usually in the mint bag. Milling marks are generally more detrimental to the grade than normal bag marks, because of their severity of depth and greater visual impact.

Minor Coin

Small-denomination coins which have little bullion value.

Mint (adj.)


Mint (n.)

The facility where a coin or bar was manufactured.

Mint (v.)

To produce a coin by stamping metal.


Act of manufacturing coins in a mint.


Total number of items issued with the exact same design elements.


Letters added to a coin to indicate where it was minted. For instance, “D” for Denver Mint.

Mint luster

The sheen or reflective qualities that are produced during the minting process.

Mint Set

A coin of each denomination produced by a given mint in a particular year.

Mint State

A coin that is in the same condition that it was when it left the mint where it was produced.

Mishandled Proof

A proof coin which somehow escaped into circulation or was otherwise significantly abused. Also referred to as an impaired proof.

Modern issue

Coins issued within the last 20-25 years.


Anything that is accepted as a medium of exchange.

Money Order

Payment usually issued by a bank or post office, for the payment of a specified amount of money.

Monster Box

Mint-issued boxes usually holding a large number of coins.


Mint State.


A polyester resin used to make heat-resistant plastic films and sheets