Some polymer clays polish better than others when trying to match the polymer clay to the surface luster of the host stone.
If I use these stones, I will still cover the filled holes with an embellishment, such as a vine with leaves or flowers, or large flower petals or leaves.
It will be better to use stone dust mixed with epoxy resin to fill holes in the future. No baking is needed and it will polish to be a better match to the host stone surface.
Note: When altered stones are used in pieces to be sold, there must be full disclosure of what was done to alter them.