I noticed after i finished making pastry that one of my small diamond pieces from my ring is missing . what could happen if my son ate it inside the pastry ? it is almost 33 mm , it is very small but has two pointed edges in the shape of an eye tear?

It is hard to eat a pastry with a hard 33mm size object in it without biting into it. are you sure of the size? for 33mm is a large size to fit on most rings. If you still think he swallowed it observe the stool to see if he passed it. But definitely take him to your MD who might get an X-ray to be sure

If the diamond was 0.33 mm or even 3.3 mm, it should pass through a person without difficulty most of the time. A 33 mm diamond, larger than one inch or 3 centimeters would likely cause a problem, but a diamond that large would be both world famous and easy to avoid while eating as long as one did not bite down directly on it.