But my favourite non-traditional forms of money are the plate money pieces from Sweden. These are generally accepted as a coinage, and are included in Krause's 17th and 18th century catalogs.
weden had minted "Plate Money" from 1644 until 1776. This huge and cumbersome coinage was necessitated both by a lack of silver, and an overabundance of copper in Sweden. Coins were issued in denominations of 1/2 Daler on up to the monster 10 Daler coin. The Daler had a value of 1/3 of a Riksdaler, which was equivalent of a Swedish Silver Dollar. These coins were not popular from the moment they were first introduced, both because of their sheer size and the weight. Any sum of them constituted a considerable effort to move around. An early account of a bank robbery in Stockholm notes that the thieves took all money except that which was in plate money, because of the effort involved in hauling it away. The largest of these pieces issued were the 10 Daler coins during the 17th century. These measured 13" by 25" and weighed in at 44lbs each.
The above coin was minted in 1716, during the reign of Charles XII. During this time Sweden was fighting the Northern War with Russia for control of the eastern Baltic, and Finland. This war was devastating to the Swedish economy and the resultant shortage of funds necessitated a token coinage which was even more unpopular than the plate money. The Government minister whom initiated this token coinage, Baron Georg Heinrich von Goertz, subsequently lost his head, largely because of the financial mess he created in his effort to fund the costly war with Russia.
In 1718, the reign of Charles XII was ended at a battle in outside of Kristiana in Norway. Charles's sister, Ulrika Eleanora inherited the throne, which subsequently was passed onto her husband, Frederik Duke of Hesse. This particular coin was issued during his reign, which lasted from 1720-51.
The demise of plate money in 1776 basically rendered the money worthless except as scrap metal. The greater majority of these coins were subsequently called in, and sold for scrap. They were useful as ballast, so they were loaded deep into the holds of ships travelling to the Far East, where they were thence unloaded and sold as scrap to merchants in Asia. One such ship travelling to the Far East was sunk in a storm in the 1780's off of South Africa. The "Nicobar" was laden with these coins. Most of the plate money available today came from this shipwreck. Any other, non sea salvage, plate money, such as the two above pieces are now quite scarce. So far this is the largest coin I have in my collection.
Sometime I hope to acquire the 4 Daler piece, but so far a non sea salvage piece has alluded my capture.