Natural stone and other fireplace and exterior detailing materials are usually specified by the architect.  Visit local sources for inspiration or take pictures of your preferences to local sources to check availability and cost.  Plan ahead to secure products that will give your home the unique, individualized look you want.  These materials affect exterior and interior colorization as does pool coping.  Travertine is available in pre cut pieces.  Brick. flagstone, slate, pavers and Marabella stone that is saw cut or honed are also popular.  Concrete (Ancient Stone) precast pieces are also available.