Yes it would.

You need portland cement. Make it somewhat wet, and mix in
just enough into the shell to lightly coat it.

Wayne Sallee
Wayne's Pets



wrote on 3/30/2006 5:47 PM:
i am trying to propagate coral and i want to make some shell grit plugs

to glue the coral on to. i know of a shop on the Gold Coast, AUS that
makes them,
but i need to know what type of glue i can use to glue the shell grit
together. it looks like a plaster of paris but that would just break
apart under water wouldn't it? any help would be appreciated.