I applaud your efforts at using/recycling the leftover material, however, marble cut for indoor installation is often not suited to outdoor applications. If it has a smooth polish, that may be dangerous/slippery. If it is thin, it will need to be mortar set on a poured, concrete slab (1-1/2" - 2" thick is best for sand set installation). Best of luck!

Thanks miles_julie
I’m hoping that I can use it because I just finished with my house and have all this left over marble almost a crate left. My daughter is looking to build a small deck and wanted to give her the rest. So if I use the blackout sheets (I don’t know what its called) then add sand and then space the tiles two inches apart and add small pebbles between them much like the picture that you posted, do you think that would work.