A semi-alive magical coin, it begins its existence as a Copper piece. If it comes into contact with another Copper coin, it will absorb that coin. When it absorbs ten Copper coins, including itself, it will transmute itself into a Silver coin. It can repeat this process, up to Platinum, by consuming enough coins to become the higher value coin, as per the standard conversion rate of 10-1. For example: it requires either 9 Silver coins, or 90 Copper coins, to go from Silver to Gold.

After reaching a value higher than Copper, the holder can break the coin in half, creating ten copies of the coin that is one stage lower in value. For example: a Gold coin can be split into ten Silver coins (or 2 Electrum if your DM uses that coin). These copies can be remerged at any time, as if they were a normal coin of that value.

A Bankers Coin can not consume a coin that is of a higher value than itself, and it counts as legal tender. 

Notes: Made so adventurers can have more control over how they store their coin, especially those of lower value. Also acts as a in-world version of the Currency tab., Creation, Control, Utility, Shapechanging, Container, transmutation