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

I would think that depending on the size/weight of the diamond, the answer could be either that it lowers or stays about the same.

An infintessimally small diamond would act like a normal icecube, which I think should keep the same water level.

A very large/heavy diamond could cause the whole icecube to sink, making the water level lower a bit when it melts since ice is less dense than water.

edit: also that icecube would not look normal. At least not unless the diamond was microscopic. Diamond's index of refraction is much higher than water's (a bit above 3 if I recall?), so it would be noticeable, just not _super_ noticeable.