Mottling in stone is a patchy or blotchy texture that can be caused by bioturbation and is often found in limestone.
    A vent defect in stone can occur when a vent is installed directly into mortar, which can cause it to break loose and allow moisture or pests to get in.This is because mortar is not flexible, so it can't handle the movement of the home or thermal movement.
    A shake defect in stone can refer to a crack or separation in stone that occurs when it is shaken.