What to fill a shell with?

What is the best material to fill a shell with?

I love shells and had been thinking recently that mounting or
setting some in silver is something I’d like to try. I’d been
thinking that I’d fill it with epoxy as Beth Rosenguard said she did
with the dentalium shell, but Lin Lahlum’s response about using wax
makes me wonder what would be best. It sounds like wax is better for
a couple of reasons.

Not having any experience with wax, I’d go for one with the highest
melting temperature. Thoughts? I wouldn’t want to use a wax that
would soften too much at body temperture.

There’s a material you can get that will penetrate and harden (does
this also mean strengthen?) soft wood. I have no idea what this stuff
is or if it is effective, but I wonder if it would work on shells.
I’ve got plenty of shells I can experiement with…

p.s. To see dentalium shell, go to Google, click on Images, type
"dentalium shell" in the search box and click the Google Search

Christine in Littleton, Massachusetts