Pics? No one can see what you see without them! :)

Stone can have small pits and voids in it, but marble is usually less prone to that than the larger crystalline structured granites are. Marble is much softer than granite though, and if not handled correctly, it can have nicks form in the surface from impacts (and normal wear like you dropping your hairbrush). You would also have some "star" formations from impact if that were the case.

Our honed marble tile in the foyer and hallway has none of this. But our honed marble kitchen counters have it all over the place, sadly. We started off without this on our honed bathroom floor, but the electrician and carpenters dropped tools and made all kinds of pits in some of the tiles. I don't think it should start out with pits in my opinion.

Whether honed or polished carrara should feel smooth and pleasing to the touch. The surface should also be flat and While a piece here or there could have some inclusions, weakness,a mark or chip those pieces can be put on the side. The reason we buy more than we need.
Marble is graded by its quality or its look. The better the look,detail and less imperfections or marks and surface features the higher the grade. Imperfections,spots,marks and anything that will degrade the overall clean look the lessor the grade .
In some cases I don't think anyone but the producer of the material may know the grade as it sets the price.
Maybe goods go thru many hands traded till they end up at a dealer .
So it is very important to check stock before making final payment as many times delivered stock may not look like the sample you fell in love with.
You have a good installer with a keen eye-you should speak with your store.

Marble is graded by its quality or its look. The better the look,detail and less imperfections or marks and surface features the higher the grade. Imperfections,spots,marks and anything that will degrade the overall clean look the lessor the grade .

I can share that we have "experienced" what srosen has pointed out re: different grades of marble. In our MB, we used a beautiful White Thassos marble mosaic from Porcelanosa as an accent in the tub surround, and as a ceiling-height backsplash over the sink. We also used White Thassos (Select?) tile/pieces from a LI fabricator/supplier in all three bathrooms to line niches and as shelves, and also used it as tub surround trim (instead of bullnose tile) in the MB.

The quality difference between the White Thassos used in the mosaic, compared to the individual tiles/pieces is very much apparent. The mosaic tile is not as "clean" or as pristine white as the individual tiles were/are. The mosaic is still quite stunning overall, but in addition to many of the tiles being less than pure white, some have streaks of grey or small spots in/on them. It doesn't detract from its beauty in any way, but that's how it is.

The mosaic wasn't cheap by any means (though we did get a terrific discount), but I am sure it would have been even more expensive had it been made from the same Select tile as our individual tile.