Marble is a strong material, but it can break. Too much pressure can break a piece of marble, and a heavy object dropped onto the surface can crack or chip the surface of the marble. If your marble object breaks, you don't have to throw the stone away. You can glue the pieces back together using a glue designed for use with stones and marble. Stone glue gives the stone a strong bond that is difficult to break. Make sure you glue the marble together correctly the first time, because you will not be able to loosen the bond to try the repair again.
Clean the surface of both stones with a soft cloth dipped in denatured alcohol. Rinse the stones with clean water. Pour a little acetone onto the marble to remove any finishes or coatings. Wipe away the acetone with a soft cloth. Allow the marble to dry overnight.
Mix one part adhesive with one part hardener or catalyst. If the package directions on your glue differs from these directions, follow the package directions for safety and best results. Do not mix the two materials until you are ready to apply the glue because the glue starts to harden immediately, and if you let it sit too long it will become unusable.
Spread the glue onto both marble pieces using a Popsicle stick. Spread the glue to an even thickness of about 1/8 of an inch on each piece.
Clamp the two pieces of marble together with a vice grip, if possible. If you are repairing a small area, such as a chipped piece of marble, then weigh down the repair area with a heavy brick or other object. Wipe away any excess glue that oozes out from the edges of the marble with a damp cloth.
Allow the glue to dry for 24 hours. After the glue has dried, sand away any excess glue with sandpaper. Wipe the marble clean with a soft cloth.