Item: 2 seashells

These 2 shells are the same, but different.  I bought one of them in a store on Catalina Island on a field trip when I was in high school.  In all of the pictures from that day, I'm carefully holding this paper bag and trying to not break my shell.  I have no idea what kind it is, but it's a spiral that just fits in my hand, an iridescent ripple of white, silver, and pale pink.

The other shell is one I found somewhere on the beach, and I kept it because it was exactly the same shape and size as the one I had, only not so shiny in places, rubbed off and almost rusty-looking.  It is broken in a few places and if I shake it there are tiny pebbles inside.

I bought the first one because it was pretty.  I don't know fully why I felt the need to pick up the second one, nor can I explain why I keep them together always and what this is supposed to signify.  I could next make a comment on appearance versus reality, or perfection versus experience, or artifice versus nature, but all of those things have been said over and over and why bother trying to make that kind of object lesson into something new?

I'm not sure it would have anything to do with anything, anyway.  It may have been as simple as an appreciation for variety - there's more than one kind of almost everything.  It turns out they look good together.