How can I remove this type of blue onyx slab from an old kitchen without damaging corners? I want to reuse it on another house as Onyx is a bit expensive.
Natural stone slabs are typically glued down if they are small enough to be moved when bumped against. Larger slabs, sometimes are staying put under its own weight, yet sometimes they get glued too. The glue used can be anything from silicone to construction adhesive. In either case, the best way to release the glue, if there is a chance of salvaging it is to remove the drawers from the cabinet and do it from the inside of the cabinet. If there is a small gap present where the top meets the cabinet, start with wood shims there, or carefully with a small metal prybar. DO NOT try to pry up all from one side. use wedges driven in a little at a time to ease the stone up. It can be done from one side, and you may need to check all sides to see if one side moves easier than the other. If you notice that one side does, continue on until hopefully it releases.