Ceramic is very stable during time. All modern media that you might think (LP? tapes? Optical disks?) require some special instrument to recover the information, other than simply looking at it (perhaps using some microscope).

Paper degrades. Plastic degrades, in general. Metals rust. But stones and ceramics tend to be very durable, including against microorganisms and chemicals. They just don't withstand mechanical forces, like a hammer. But anyone willing to use a hammer would use any other thing to destroy other medias, too.