I don't imagine you would have to coat the fake jewels/gems, as they would probably be plastic, glass, or crystal. I tend to like epoxy for coating things.My 29 Biocube saltwater setup looks halfway nice to me, but I think it needs some tweaking. I walked by a bead shop the other day, and it gave me an idea. That idea is, I'll get a small, old-fashioned wooden chest, bang a couple of holes in the sides, and coat it in some kind of acrylic.
Then I'll fix a platform of some kind into it, making it only about 1 3/4" deep, and put white sand on it. I'll then find some realistic 'sunken treasure' decor, maybe some gem-like stones too, coat them in acrylic, and arrange them in it so it looks like the chest just sunk. I'll then place the rockwork around it and add some more treasure around the chest.
The idea is to make it look like it just sunk there and has been there for a while. I'd place some corals on and around it, and get a few more snails so they can keep it mostly algae-free. Yes, that's possible, especially when you have a tuxedo urchin.
I was thinking that I'd also find a small pistol shrimp, put him in the chest itself, and let him burrow under the treasure. I could partner him with something little and bright, like an antennae goby.
Do you think this could work without looking fake? Any ideas? Any imput on what acrylic to use as a clearcoat?