I am about to pull the trigger on the 3 or 5" honed marble hex tile for my kids' bathroom. Where do I find the slippery factor information?
On another note, is 3" too much grout for a kids bath?
You ask the manufacturer for the COF. In general, even honed marble would be too slippery for a kids or older adult's bathroom as it's usually under 5 even when honed. For a master bath, with grippy rugs down, it might not be too bad.
I would think that the more grout would be good for a kids bath with this marble to help provide traction. Have you thought of using epoxy grout? I read that it is more stain resistant. And I believe Bill V once commented that while epoxy may be over kill in the home setting, if you have pets it would be justified (paraphrased). Kids are like pets aren't they?...;)