Firstly, a reliable provider of stone material must be selected. There is great difference between stones ordered for your kitchen top and stones ordered for your pool. Of course, experience remains a factor of great importance.
Reliable providers, spent a lot of money in research and lab tests to have results for strength of all types of grates.
The correct drain grate must be selected, Existing models are separated for light use or heavy duty use
Drain grates of 2nd generation, the sandwiched models, are mostly advised, where the upper layer is a decorative stone and the lower layer is either porcelain or artificial stone or even stainless steel plate.
Always apply the anti-shock tape underneath both stepping of drain grate.
Test carefully that drain grate is properly fitted into the channel.