Hiring a professional stone contractor can be difficult.  A careful reading of this report should give you enough background to know what a professional is talking about.   Here are some points you should definitely cover before arriving at any decision:

1.  Before calling any contractor, ask around.  Have any of your neighbors had their marble/tile done recently?  Who did it, and were they happy?  Call your local stone/tile suppliers and ask whom they'd recommend for this type of work.  Some of the stone/tile Associations may provide recommendations.  And, of course, there are always the Yellow Pages.

2.  Once you have located several companies, schedule appointments to receive estimates.  Almost every contractor I know will perform a free estimate.  Be sure you are there for the scheduled time; it can be very frustrating for a contractor to arrive for any estimate, only to find no one home.  On the other hand, if the contractor fails to show for the scheduled appointment without at least calling, he obviously isn't interested in your project.

3.  When the contractor arrives, explain what your concerns are and what you are trying to achieve.  After all, you live with the floor every day; the contractor is seeing it for the first time.  Give the contractor as much information as possible.  What do you use to clean the floor?  Has the floor been polished? Is there any wax or coating on the floor? If it's a new installation, the contractor will also need to know what materials are on the floor now.  Any information will help him decide how to fix the problem.

4.  Once the contractor has determined what is needed, ask him to explain the procedure he intends to use.  Are there other options?  Reread the section on restoration and polishing and ask specific questions.  What polishing process will be used, etc.?  A competent contractor should be more than happy to answer any question you may have.

5.  A word on negotiating price: among contractors, as in any occupation, personalities vary widely.  Some contractors will negotiate; others will stick to their guns, although if you mention that you are getting two additional estimates, even a stubborn contractor may sharpen his pencil. Above all, make sure you're comparing apples to apples.  If one contractor is only going to polish and the other is going to grind, the difference in price will be considerable.

6.  If possible, obtain a demo or sample.  Ask if a free demo can be performed; have it performed in a representative area.  This will indicate what the final job will be like.  Be reasonable, however; don't expect a contractor to perform a demo if the job is too small.

7.  Ask for references, and check them.  Many contractors in all fields have references, but you'd be surprised how rarely they are actually checked.  Call at least three and ask if the contractor did a good job.  Were there any problems and did he correct them? Where his employees professional?

8.  Does the contractor carry insurance?  Ask for proof.  Have him show you a certificate of insurance, or, if the job is large enough, have his insurance company send you one.  Be sure he carries liability and workers' compensation insurance.  Any reputable company will carry both.

9.  Once you choose a contractor, schedule the job. Don't be surprised if the contractor is booked for several weeks.  Be patient; a good contractor will be busy, and you will have to wait your turn.  If you absolutely must have it done now, ask him if he'll book you if he gets a cancellation.

10.  Gut feeling:  are you comfortable with the contractor?  This is much more important than you might think.  Even the best contractors can make mistakes.  The difference between a good contractor and a bad one is the willingness to correct those mistakes.