.125 = 12.5% so, in essence mainly not silver - likely to be nickel amongst other base metals
It means that its 2500
If the necklace is silver it means it was made using Sterling silver.
It is a silver mark. It means 82.6% silver (high content but not sterling which must be 92.5% [925 mark]).
Hallmark 962
The 925 hallmark is indicative of 92.5% Sterling Silver.
H100
RSG stamped on a silver ring likely stands for "925 Sterling Silver," indicating that the ring is made from 92.5% pure silver. This stamp is a common hallmark used in jewelry to show the silver purity level.
Electroplated
That would be the hallmark, which is usually the initials of the designer. i.e: "ALE" on Pandora bracelets stand for the founder of Pandora jewelery.
It is French importation hallmark. It means that your object has been imported into France.
worldwide
It means 100% silver