Charcoal/silver/blueish shiny color plate from Kyoto

Hi there,
Wondering if anyone can help me out to identify what kind of Japanese plate this is? I have purchased it over 13 years ago in a local pottery store in Kyoto, Japan. It is the only plate I have every come across with such an interesting charcoal/silver/blueish shiny color. It has no signature of any kind... It's so weird, I decided to just buy it as souvenir. If anyone has any info of this type of Japanese pottery plate, purpose of use, etc.. Please let me know. Thanks!!! Much appreciated.