Hi, I use granite and marble floor tiles for my jewelry display, and
I break them into irregular shapes to make the display interesting.
You could do the same thing, only break the tiles into pieces that
fit the size of your pendants. If you want clean, finished sides, or
if the tiles are too thick, I'm sure there is a lapidary in your area
who can do whatever you need to make your stones work in your
designs. The tiles are relatively cheap, $5 to $10 for a 12" x 12"
tile, and there are many stone-types available. If you can find a
flooring company with what they call a "bone pile", leftover tiles
that they sell at a discount, you can do even better cost wise. If
all else fails, let me know, as I have plenty of Calif. Sierra
granite I could cut into pieces just as you describe. Good luck!