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Inside the Mint


Coining a term

The world of coins can sometimes be confusing. We'd like to make things simpler!

Describes gold of extremely high purity (only 10 parts per million impurity).

Describes 24-karat gold of high purity (only 100 parts per million impurity). Used to designate Gold Maple Leaf bullion coins.

Process of heating and cooling metal strips in a low-oxygen furnace in order to relieve stresses.

A chemical toning process used for medallions which prematurely tarnishes the coin to simulate the natural darkening that occurs as metal oxidizes with age.

To test the weight and metal purity of a coin, wafer or bar.

The blank metal disk that is eventually struck and turned into a coin.

Brilliant uncirculated
A brilliant relief is struck on a brilliant field. Brilliant uncirculated coins are struck up to two times on numismatic presses.


Process by which the image is struck onto blanks using a die engraved with a mirror image of the design.

Process by which any remaining oil residue is removed from blanks after they are washed and before they are minted.

The artist's rendering on the reverse side of a coin, along with any words, nominal values, decorative elements, colouring, hologram effect, etc.

A tool that strikes an image or relief on a blank, turning it into a coin.

A portrait found on the obverse side of a coin. Canadian coins bear effigies of the reigning monarch, Canada's official head of state.

An artist's design that has been adapted and transferred to a medium that will ensure the best relief for minting.


The appearance or surface texture of the coin's relief.

The process of manufacturing coins.

The 'heads' or face side of a coin.

Coins with a frosted relief over a brilliant field. Proof coins possess the highest-quality finish for a numismatic coin, and are usually struck twice to reveal the smallest details of the coin's design.

Grooved or serrated lines found around the edge of some coins.

The relief is the raised or three-dimensional image found on a coin's field.

The opposite of obverse – the 'tails' side of a coin.

Reverse proof
High-quality proof finish in reverse: brilliant, reflective details on a frosted or slightly matte field. These coins are individually passed through the presses. Multiple strikes are applied to achieve maximum detail and finish.

The raised portion that runs around the perimeter of a coin.

Gold, silver and other metals for coinage start out as cast bars. They are rolled into strips, each specific to the size and thickness of the minted coin.

A brilliant image relief is struck against a matte or lined background in order to achieve maximum visual impact. Specimen coins are struck up to two times on numismatic presses.

Either a circulation coin that has never been circulated or a coin with a brilliant field over a brilliant relief.

Process by which rimmed blanks are tumble-washed in a drum and dried by hand.