As a one-dollar silver coin, a foreign silver coin, is regarded as bare metal, its pure silver content, 23.2g, is valued at 60g of common silver currency (Tenpo Chogin), because 10 monme (37.5g) of pure silver is purchased at silver mint for 97.5g of Tenpo Chogin.
また1ドル銀貨すなわち外国銀貨は地金と見做されるため純銀量6匁2分（23.2グラム）に対し二六双替である通用銀（天保丁銀）16匁と評価される。