By their nature Abalone and Pearl are not as tough as other natural materials although they are more stable in general than most if not all other natural materials. They might be more prone to chipping or cracking if dropped or abused and might be more prone to show scratches say if dropped or rubbed even a little on concrete, but neither is so delicate that they can not be carried and used and still look good year after year with just a little more care as to where you put the knife down. I have just gotten into the habit of slipping them back in my pocket after they are used.
In short, I think that if you are willing to take a tad more care, they make for a very stable out of the ordinary handle material.