It is typical and customary that your were quoted for stone by the square foot. If this is the case, you did not actually buy whole slabs, you only bought the square footage to make your countertops. You selected the slabs to have them made from.

On your invoice or contract it should clearly quote you a price for your counters. If it does it does not entitle you to the rest of the stone slabs. Perhaps you were quoted by the square foot, which again would not entitle you to the rest of the slab. On the other hand if your contract or estimate quotes you by the slab, the rest is yours.

FYI: The stone itself is about 1/3 the cost of a finished countertop. The labor, tooling, overhead and freight to make it fit a specific application are all greater costs than the stone itself. We average 25% waste, and know
this before we come up with a cost per square foot to make countertops. We also know that remnants are essential to recover our waste and manage that waste cost down to 25%.

If I understand you correctly, the slab is slightly dipped. Your installers made it perfectly level front and back and yet it seems to dip in the center of the seam just on one side. You didn’t tell me by how much or if the stone is resin treated. These two factors need to be considered prior to making a decision to “top sand” or Top polish the seam.

This can be “Top polished” so that it feels smooth, however you will be removing the baked on resin finish (if your stone has one) and reflecting light differently (due to a different polish only on the seam) which may actually draw more attention to the seam than you intended.

My advice would be to find out if it is a resin treated stone before making your decision and measuring the lip. If the lip is very small it may not be worthwhile to top polish it perfectly smooth. The trade off is it may feel perfect but look imperfect. Not all stones are resin treated. I do not know if yours is. About 90% of all available granites are resined.

You have to remember that it is stone and a product of nature, so there may be hard and soft components within the slab. This may contribute to the surface not being perfectly flat despite the fact that it was all polished in a machine designed to face polish stone evenly. The stone itself may not be consistent lending to some areas being a different thickness than others even within the same slab.

The resin treatment will help to keep the stone from staining. Removing the resin treatment in only one area may also have the stone “AGE” differently in just that spot. Aging is the natural color change that happens over time. An even resin coating will allow the stone to age and patina evenly over time. Removing the resin in one area exposes the raw stone to light, soap, oils and other common counter-top items that may age the stone (just in the spot you instruct the fabricators to remove the resin from).

Before making the decision consider the side effects and the overall look as well as the feel, understand the trade offs and then make your decision.