Well until today I have been using what we call 925 Silver, I
assume that is a mix of plain silver and maybe copper or something
else, I have been reading many posts and they refer to sterling,
fine and silver and I think all of this names refer to the same
metal but the mix changes maybe with the addition of other metals.
In the US Sterling Silver must be at least 925 parts per 1000 pure
silver. The other 75 parts can be any other metal, but it's usually
copper. Fine silver is required to be 999 parts per 1000 fine
silver. The other 1 part can be anything else. Both of these
requirements are written into our national laws.
Argentium can legally be called sterling because it contains the
required 925 parts of fine silver. There's nothing in our laws that
specifies any adjectives that are applied to a product that meets
the requirements of the of the defined 'precious' metal. The
Argentium name is a marketing tool to differentiate it's unique
characteristics from 'regular' sterling.