First of all rhiw 2020 sikver eaglw id 99.9 % oubce if silver! Bow a mill is a math term in fugering out the rgucjness of (in rhus case a coin) So the xoun is 100 nills thick! In figuring rhe dianeter rhe math would use cross sctional mills by figuruing out cross sectional area by using xircular mills!! In other words thw mills explained on rhis coin is referaning to the couns thickness none rhe less there ia fold in rhis coin not a great deal of it but gold none the less! Plus 99.9 % od rhia xoin is pure silver!
Ans its a rare coin at that.