Can You Solve this Ice Diamond Riddle? ft. Vsauce’s Michael Stevens

I think the level rises. Ice didn’t sink in the water, so its melting increased the level of the water. I’d say the water level increased by the volume of ice cube (w/ diamond in it). Assuming water in solid state takes as much volume as water in liquid state. I don’t think that’s assumption is valid though. Then it depends on how the volume changes with the change of physical states and volume of the diamond itself.