This is the largest collection of real and some fake money from the Avatar The Last Air Bender series. I was going to to make an engraving plate for the paper Yuan but it failed hard. Most of these are based on what we see in the series pictures above. there are two Fire nation silver pieces as the coins show in Aang's hands aren't the same as those Toph's counting. the pieces Toph's counting seem to be ice cream coned shaped with a prominent triangular point hidden behind the gold pieces (seen from a different angle) and a rounded multi-sided section which we can see in the image above. The only thing to mention is that Toph's parents pay Xin Fu and Yu with ingots called Yuan Bao to find Toph

these can be found here made by Samson
https://www.thingiverse.com/thing:235419

Meanwhile there are some fake coins/ingots which likely would exist but we never see. For instance, while Water tribe money is relatively primitive it would be necessary for them to have coins of differing values. in this case i used the idea that they would use the phases of the moon ands waves for different coin structures. I also kept the cut out from the middle in most of the coins. Meanwhile, Water tribe currency ingots would be similar to the Yaun Bao but resemble canoes and be stackable for easier movement. Each ingot would be stamped with the official symbol of the northern water tribe to make it known that these ingots were official rather than counterfeit.

For the earth kingdom we have a simple change of color for most of the coinage; however, when looking over Chinese coinage i found the symbol for the kingdom looked similar to spade coins. This would make sense as the Earth Kingdom Symbol is of their coinage most likely to signify how strong and stable it is, both the kingdom and the currency. This could mean that the symbol for earth was based on an earlier form of currency that was used throughout the earth kingdom and was so stable that it was used by other nations as well. This would explain why all coinage throughout the world have raised edges and the angular shapes seen in the firenation. Meanwhile, the Earth Empire would have kept much of the Kingdom's money to begin with. However, its likely earth kingdom money lost much of its value as political insecurity leads to economic insecurity. This would have likely meant that they would have updated to the new Imperial standard with an octagonal design. Similar to the new flag.

designs used
Metal clan emblem by Hearse6669
https://www.thingiverse.com/thing:2590700

The Fire nation would have had Ingots of some sort. We see their metal working ingots which are basically metal bricks. However, currency ingots would look similar to clay oil lamps or dragon eggs. (Use any egg design you wish just cut off the bottom so it can sit up)

Designs used
pitcher by eleode
https://www.thingiverse.com/thing:4378576

In the United Republic we only see one type of coinage as most money is paper but its likely that since its based off of the United states coinage would still be used. These would be parts of a single Yuan like .01, .05, .10, .25, .50, with only the 1 yuan having both a coin and paper currency.

As for the Air nomads it is unlikely that they would have had coins or money but rather barter for most of the goods they needed. When or if money became necessary its likely they sold their goods for money and used the money of the nations they traded with. This would be similar to how Native Americans acted with colonial powers. Its likely that there was a room somewhere where they held foreign coinage for use in business deals if it came to that. Though its likely they got most of the resources and services they couldn't do themselves. through donations, like how Buddhist monks use alms bowls, or services, like clearing spirits. However, if they did have a form of currency it would resemble wind chimes. Meanwhile, the largest ingots would resemble alms bowls

designs used
bell by CTLS
https://www.thingiverse.com/thing:194202

Bowl By AK_Eric
https://www.thingiverse.com/thing:32655

bison whistle by DTuininga
https://www.thingiverse.com/thing:2166169

arrowhead by daniel_bingamon
https://www.thingiverse.com/thing:1216593