More pictures ..

Agreed....more precisely oyster shells...

Thank you both .. any idea of country of origin?

Probably Japan....or China.

FWIW, mother of pearl can be obtained from other shells as well. Abalone is one.

Thanks again, another question .. what is the box in this "set"? There are 2 napkin rings, a corkscrew and a box. What would the box have been used for? (I looked on eBay and found a box with the same tree that was labeled as Chinese.) Tea, sugar???

Maybe there were other items now lost in the sands of time?

Might the box be for holding those items, and maybe others? A souvenir/gift shop item?

They might not be a set at all. They just "go".

I think Fori's thoughts are good....black lacquer with inlaid mother of pearl is fairly common and since the patterns are different, I suspect it's just a collection of that type of ware. The box may have been for cards or perhaps a gentleman's dresser box for his cufflinks etc.

And Abalone shell is quite different from oyster shells in appearance.

Would the box hold recipe cards?

It could...if they are the right size....but I doubt it was originally meant to.

The box is about half the size that I normally see for recipe cards.