Prepare to clean the chipped marble to remove accumulated grime. Put on gloves, since acetone is involved in the cleaning process.
Dampen a rag with acetone. Wipe the chipped area of the marble floor to eliminate all grime.
Moisten another rag with water. Wipe the chipped marble to rinse off the acetone.
Dry the chipped marble with a soft towel.
Squeeze equal portions of a two-part epoxy glue system onto a mixing board. Mix the parts with a flat wooden stick.
Brush the mixed epoxy glue onto the chipped marble fragment using a disposable paintbrush, then fit the fragment into the gouge. If you misplaced the chipped marble fragment, simply brush the epoxy glue mixture into the gouged marble floor.
Wipe any excess epoxy glue mixture off the repaired marble, using a clean, acetone-moistened rag.
Lay a book on the freshly-glued marble fragment to hold it in place. Let the glued-in marble fragment or glue-filled marble floor air-dry for 24 hours. Epoxy glue system curing times vary, so read the manufacturer’s instructions.