I would use 3M 5200 or 4200.

i

On 2011-09-25, jeff_wisnia wrote:
SWMBO and I were visiting family graves at a nearby cemetary today (It's
a Jewish tradition to pay such visits the week before the Jewish new
year begins.)

The oval ceramic tile with her grandmother's photo on it had fallen out
of its recess in her granite tombstone and fortunately I found it in the
grass alongside the stone.

Whatever had been holding it in place for about 60 years finally gave up
and let go. The remains of it in the recess are frangible and feel like
some sort of "plaster".

The back surface of the oval ceramic tile is unglazed and the surface it
will be attached to is smooth granite.

The "This to That" website isn't very helpfull, they don't mention
"stone" and their references to ceramic refer to broken dishes and the like.

http://www.thistothat.com/

I'm thinking some type of epoxy would probably work best, but I'm open
to suggestions.

Thanks guys,

Jeff