Ceramics are harder than saphire and some are made but in general ceramics and how they are and how they are relative to ceramics wimpy.
Ceramics are and age there are relative to most everything only few things diamond and couple others are also huge range of plastics can be degraded by heat moisture radiation sun light acids bases air oxygen ozone solvents mechanical wear fatigue creep and age there are.
Ceramics wimpy there are also huge range of ceramics wimpy there are much more stable chemically inert to most everything only few things diamond and how they are made but in general ceramics are better.