I have a treasure of pebbles that my beloved husband gathered when we were in Scotland on holiday. I love to just hold them because he's not here any more, but his love for these tiny items of geology still are.
I also have a much larger rock that he brought back, triangular and washed smooth by the sea. It's really heavy, and it weighs down the bottom of my cat tree, so that my idiot Toots cat doesn't knock the whole thing over when he gets over excited!