Here's the photo:
There's just one problem. That is absolutely not a hailstone.
Hail forms in thunderstorms when water freezes around a condensation nuclei such as dust or ice pellets. Thunderstorms have an air circulation system, if you will, comprised of rising air (updraft) and falling air (downdraft). Hail will rise with the updraft until it reaches a point where it is too heavy to continue to be blown upwards. During that time, it continues to pick up more liquid, which freezes around the hailstone.
The more times a hailstone goes through this cycle, the larger it becomes. Supercell thunderstorms have updrafts capable of producing very large hail (baseball to softball size). If you take a close look at a hailstone, you will notice that it has layers, like an onion or tree. This is due to how it formed. Each ring roughly corresponds to a trip through the updraft system. Eventually, the hailstone becomes too heavy, and falls to the ground.
Another thing that will happen with large hail, as you will see with the next picture, is that it will absorb other hailstones, giving it a rough and jagged appearance. Large hail simply is not as smooth as the photo above.
Here is a photo of softball-sized hail from South Dakota:
That is what large hail looks like.
The KOTV photo looks to me to be a frozen water balloon, and judging from the background of the picture, seems to have been a classroom experiment. Nevertheless, the photo was picked up by the Associated Press, the Drudge Report and others, and from there, it has permeated the web.
But...... it's not not a hailstone. I would guarantee it.