NGC Error Coins & Mint Varieties

Question 1

What is a 'doubled die' error in numismatics?

Accepted Answer

A coin where the die itself received a doubled impression during the hubbing process, resulting in doubled design elements

Answer

A coin struck twice by two different dies

Answer

A coin that received two separate strikes from the same die pair

Answer

A coin produced with a misaligned hub during quality control

Question 2

In numismatics, what is a 'mule' coin?

Accepted Answer

A coin struck with obverse and reverse dies not intended to be used together

Answer

A coin struck on an improper planchet

Answer

A coin struck with excessive force causing design spread

Answer

A coin rejected during the mint's quality control process

Question 3

What is a 'broadstrike' error coin?

Accepted Answer

A coin struck outside the retaining collar, resulting in a wider and flatter coin

Answer

A coin struck with misaligned dies causing a wide design

Answer

A coin struck with excessive die rotation beyond 45 degrees

Answer

A coin struck on the wrong planchet for that denomination

Question 4

What does 'die rotation' refer to in error coin collecting?

Accepted Answer

The angular misalignment between the obverse and reverse dies, measured in degrees

Answer

The spinning motion of a die during the striking process

Answer

The scheduled replacement of worn dies during a production run

Answer

The process of rotating dies to evenly distribute surface wear

Question 5

A coin struck on a planchet intended for a different denomination is classified as which type of error?

Accepted Answer

A wrong planchet error

Answer

A mule error

Answer

A transitional error

Answer

A planchet mismatch variety

Question 6

What is a 'struck-through' error on a coin?

Accepted Answer

An error where a foreign object between the die and planchet during striking leaves an impression on the finished coin

Answer

A coin cancelled after minting by the mint for quality control

Answer

A coin struck with a severely cracked die

Answer

A coin struck with excessive pressure that created a raised outer rim

Question 7

The term 'transitional error' in U.S. coinage most accurately describes which scenario?

Accepted Answer

A coin struck on a planchet or with a die from an adjacent year, typically during a design or composition change

Answer

A coin produced during a move between minting facilities

Answer

A coin produced at the very beginning or end of a die's productive life

Answer

A coin struck between proof and business strike production runs at the same facility