mintage

In addition, due to their rarity, numismatic coins also hold value based on their age, condition and mintage numbers.

There are so few because, at the particular point in 2009, there was low demand for 50 pence pieces, and that resulted in a low mintage - or production run - of the Kew Gardens 50 pence.

It’s that low mintage that gives North Korean coins their value among collectors.

The Singapore Mint, which this week unveiled a commemorative medallion for the summit, later raised the mintage for the gold and silver medallions after an overwhelming response.

The coins will be a limited mintage of 7,500 and will cost £80 each from the Royal Mint.