Hello! Could someone who is familiar with Grey Lueder please help me out? We have grey lueder coping around our pool and on our retaining wall. I understand there will be color variations, but we also seem to have texture variations. Some of the pieces are uniform in color and others are very marbled with darker grey spots. The ones that have the darker grey marbled through them already seem to be eroding. They are already getting holes in them. My question is how do you know good quality lueder verses lueder that is not fabricated well and will continue to erode. Should we have them replace the marbled pieces? If you zoom in on the attachments you can see the small holes forming.