It would seem to me that if you were wearing the watch, the load would vary from one area to another and any shock could cause the crack to enlarge or shatter the jewel. A good watchmaker should be able to rejewel it but it may require it to be rubbed in or reset which would require a careful match of color so the repair is unnoticeable. All depends on how much you have to spend and how often the watch is used. In any event, the watch may not keep good time with the crack when worn. Just my 2 cents.