This is a hatched puffin egg. The beauty of it is mostly in tact. A beautiful speckled puffin egg:

(Photo Source: http://www.flickr.com/photos/28190483@N07/3650595298/)

Both parents take care of the puffin eggs. The male puffins build a nest for the female. Then the female lays generally 1-5 eggs. Puffin parents are very protective guarding their puffin eggs diligently until they hatch approximately 40-43 days later.

Here are some photos of puffin eggs.

Horned Puffin Egg

Atlantic Puffin Egg

Female puffins lay one egg and care for and protect it accordingly. If they only have one, it is important to ensure it survives. Both parents incubate the egg by holding it against a brood patch with their wings—one at a time. Once it hatches both parents also care for the young taking turns feeding it and watching it.