I bought a collection of odd, curious and primitive money some years back that was being de-accessioned from the Detroit Museum of Art (could be Detroit Museum of History).
The coins are labeled "Indian Dump Coins" and I had never heard that phrase before. I gather than "dump" coins refers to coins that are extremely thick. And these are!!
21mm diameter, 7mm thick
17mm diameter, 5mm thick
16mm diameter, 5mm thick
I will note that I have found some of the muesum attributions to be flat out wrong.