Can anyone identify the mark?

Hello everyone,
My name is Duarte and I’m from Portugal.
I’ve got several forks and spoons with this mark. Is it silver 0.835? if so, what is it worth?

thank you all for your attention

best regards

I think the maker/company is Ercuis, founded in 1867 in France. I have seen a similar symbol with 84 on electroplated pieces.