cleaning with vinegar seems to have reduced the shine
Hi Kirsten: Give these sites a peek, they should help:
You can reseal natural stone. I have a sealer that just wipes on.
Here's a video tutorial: https://www.youtube.com/watch?v=4jtY0Oc4Ztg
First, vinegar is a fantastic cleaner for many surfaces, but NOT marble, granite or any natural stone. The acid in the vinegar ate the finish off. You have options though. You can call in the pros to resurface for you - can be expensive, or apply a sealer that will get it back to a more aesthetically pleasing appearance. My vote is to shop for the sealer at a granite and marble stoneyard or supplier, they typically carry better products than your average home improvement center or hardware store.