I was given 4 pcs of very nicely shaped white coral rock and was wondering if coral could be used in a root over rock bonsai.

The calcium content is very high and I don't think many trees can take it.

Does anyone know for sure?

If coral can be used only on certain trees what are they?

I know many of he islands in the gulf of Mexico are coral Islands and there are trees all over the place.

Thanks for the help

Paul