To the initiated this only adds to the allure of the precious objects.
The tradition of jewelry manufacturing in the USA started only around 1840 and one can find many pre 20th century pieces in the USA stamped with European marks.
By that time the general taste had changed from eclecticism to Art Nouveau and Edwardian.
Thanks to the hallmark research that began in the late 1800s, a good picture of hallmarking practices throughout the ages is now readily available.
Paying taxes has never been on the priority list of entrepreneurs and some gold and silversmiths in Germany and the Netherlands started stamping marks on their jewelry and silver work that mimicked antique hallmarks.
The most encountered hallmark on jewelry is undoubtedly the "purity" mark which indicates the total amount of gold or silver used to manufacture a coveted jewel.
This changed around 1840 when falsified hallmarks, named "pseudo marks" appeared on the market to dodge taxes.
In those days the English government raised taxes on imported gold and silver work, with the exemption of antique items.
This deceit lasted to around the turn of the 20th century.
Many collectors and civil servants responsible for tax collection, had no understanding of foreign antique marks.