Second only to Tungsten Carbide, Black Ceramic is the most scratch resistant material used to make rings.  It is jet black all the way through-- its color is not a coating.  It is permanent and will not corrode.  This is not the "ceramic" of a commemorative plate.  It is a seriously advanced material principally used in the aerospace industry.  Though lighter than tungsten, it still has excellent heft. It gives every impression of being a metal, including a satisfying clink when tapped.   An excellent choice and my recommendation for a non-conventional, maintenance-free wedding band.

Comfort fit.

Hardness guide: