Well, it makes no sense otherwise … if Black stones are also made from a shell then:
a) why call them slate and shell and not just “shell”
b) how come noone talks about the grain of the black stones and they only care about the white ones?
c) that slab that is sold for paperweights does look like a rock and it has no curve. If that is a shell, then it must have been so huge, that I could probably sleep inside that monster
Edit:
Went to Kuroshi and found their most expensive slate and shell product. Those stones cost 40.000 Euros. If they are using black clams, then that would have been the product to have an “all shell” sale.
Turns out, they are stone: “All clamshell stone sets includes black stones, as well, which is made from Nachiguro slate stone.”
Sounds shellfish to me
Imagine if the post office lost a 40.000 euro worth of parshell … not to mention that every day that it was slate in arriving, you would be unshelltled until the box arrives and everything feels exshellent again.
Ok, let’s wipe the slate clean now or this topic will turn into a pan full of shell puns
The stones are size 30 (about 8 mm thick), snow grade. Perhaps @Soromon could provide more information about the set. I believe the item number is c071, but the information page for it is now offline.
The backgammon set was purchased earlier from a separate retailer.