Pictured below is the bottom of a cultured LPS coral substrate brought into AquaCorals.

I am all for cultured corals (man made & grown out in the ocean) but people need to be aware that many of the so-called "rocks" these cultured corals are mounted on are also man-made substrates and sadly, too many times, I've found they contain metal which is a toxic contaminant.  Seen in the picture here, rust areas which indicate metal corrosion once in our tanks.  Given this I always recommend that the cultured coral is carefully removed from it's substrate & glued or mounted in some fashion to a real rock.

Whenever possible we should all favor the purchase of tank raised (like my AquaCorals corals) whether aquacultured or cultured.  Just be careful you aren't introducing potentially harmful substances as well.  This goes for man-made plugs & other substrates which often leech phosphates & other contaninants.  At AquaCorals almost every coral offered is mounted to pure ocean rocks.  Protect your tank & your investment.