<P> In the early United States , no national assaying system was adopted , although the city of Baltimore did maintain its own assay office between 1814 and 1830 . Prior to the general adoption of sterling silver as the standard of purity in 1868 , silver was generally obtained from the melting of coins . Since these could vary considerably in purity , from around . 750 millesimal fineness to around . 900 , silver known as `` coin silver '' varies in purity . Silver at that time was sometimes marked `` COIN '' or `` PURE COIN '' , but can also be without a standard mark altogether . After the adoption of the sterling standard , pieces were marked with `` STERLING '' , the number `` 925 '' or the notation `` 925 / 1000 '' . </P>
<P> In the early United States , no national assaying system was adopted , although the city of Baltimore did maintain its own assay office between 1814 and 1830 . Prior to the general adoption of sterling silver as the standard of purity in 1868 , silver was generally obtained from the melting of coins . Since these could vary considerably in purity , from around . 750 millesimal fineness to around . 900 , silver known as `` coin silver '' varies in purity . Silver at that time was sometimes marked `` COIN '' or `` PURE COIN '' , but can also be without a standard mark altogether . After the adoption of the sterling standard , pieces were marked with `` STERLING '' , the number `` 925 '' or the notation `` 925 / 1000 '' . </P>
when did they start using 925 on silver
when did they start using 925 on silver
1868
1868