How to clean and maintain tumbled marble in a shower?

My husband (who worked for a granite company) recommends the following: for the cracks and parts that are falling out you can use an akemi epoxy (Akemi Stone adhesive). Only mix up a little bit at a time as it dries out very quickly. You can also add a little color (any dye will do) to it in order to match it to the color of your marble. Apply it with a razor blade and make sure you work it into the cracks as much as possible to get a good seal. Let it dry thoroughly (according to the glue's specification, 20 Min should be fine). Afterwards sand the whole thing done, best with sand disks starting with 400-600 grit. You wil have to keep it as flat as possible to polish it evenly and try not to hit any cracks - this way you will get the shine back. Then gradually work your way up to higher grit numbers up to 3000 grit (you should not to have to go any higher). This will make it really shiny! Any nicks you might cause with the grinder you can fix with the Akemi again....

Afterwards use a stone impregnator on it to seal it and keep water from entering into the stone. (this will have to be re-applied every couple of years).

For cleaning purposes on a regular basis you should only need a soft cloth and warm soap water from then on, since the impregnator should keep most of the dirt etc. from building up.

I know, it sounds like a lot but it will make it look like new again :)

To clean it. C.L.R. makes a bathroom spray for buildup. Don't know if you are going to repair the marble. But the yellow bottle of C.L.R. is about 4 dollars and it sells at home depot.

Once you have repaired the damaged stone, try applying a good quality car way with a soft rag over all the stonework. Water and soap will bead right off! You won't have to scrub away soap scum and it won't cause any further damage to your stonework. This works on tile and grouting too and will prevent grouting from becoming discolored.