Ice Diamond Riddle SOLUTION ft. Vsauce's Michael Stevens

I would add, that there is a minimum about of ice required to float the diamond so cube density < 1. As the cube melts, the diamond ice density approaches 1. When the diamond ice density > 1, then diamond ice cube will begin to sink to the bottom. The diamond ice cube will then continue to melt, with the liquid line lowering until the ice is gone. At some point, the ice may release from the diamond and surface. then the liquid line would remain constant.