That brings back some memory.
As a kid i had a bunch of these Anker stones:
https://en.wikipedia.org/wiki/Anchor_Stone_Blocks
Those where awesome.
Kind of like Legos but made of some stone like material
Somewhat of a different use case i suppose.
My google-fu isn't working well today otherwise I could find a reference to this toy (I can't recall what it was called).
Well love stones acquire an awesome, soft, rounded off shape.