I have a large lobby of white marble and when we mop it there are streaks left on the floor. How do we eliminate the streaking?

It sounds like you may be using an improper cleaner in your mop water or you are using a dirty mop. Try switching to a daily cleaner specifically designed for marble flooring. Also make sure the mop is clean and that it is only used for the marble flooring. In other words, do not use the same mop you use to clean the quarry tile kitchen floor to clean the marble lobby.

Designate one mop exclusively for the marble floor. Mark the handle of the mop and keep it clean.

TIP You may also want to cut back on the amount of cleaner you are using. Try using up to half the recommended amount of cleaner concentrate in your cleaning solution.