Silver hallmark on spoons

Hello, I have a couple of spoons that seem to be silver (according to home made tests), however they are unmarked. The only inscription is in the bowl.of the spoon and is this: either 000 or OOO or three circles… have any of you encountered this mark? or does anyone know what this stands for, if there is any info about it. I have been breaking my brain searching about it online but haven’t found anything.
Thank you!