What is Ceramic Microphone?
A ceramic microphone element works the same way. The Rochelle salt is not very strong and crumbles easily. If you drop a mic or let it freeze or it gets too hot the element breaks in half and is useless. Stronger materials with piezoelectric effects similar or even stronger than then Rochelle salts have been discovered over the years.
The Rochelle salts absorb water or become permanently bent so that old ones have low output. Ceramic elements work exactly the same way as the Rochelle salt microphones, using the same internal parts, except that it uses a small slab of a piezoelectric material made out of a ceramic compound. The ceramic elements sound much like the crystal elements.
Crystal and Ceramic microphones are considered low quality and although they are better than carbon microphones are usually used where low cost is more important than good sound reproduction.