I had my mammo the other day. I asked her how much they weigh. She said it all depends on density and a few other things. Someone with my size may have much lighter ones. I have very dense ones. (Hmmmm. That must explain why I am in danger of getting a black eye everytime we go over a speed bump.) She also said that someone with implants might weight more than someone without depending on the type of implant and where it was implanted. So, your question is probably still unanswered, but at least I remembered to ask.

An Engineers volumetric approach to determining breast weight using bird seed (or kitty liter), your bra, and the plastic tub from one pound of lard (note the fill line). Assuming breasts have approximately the same density as lard. How many #1 tubs of bird seed does it take to fill your bra cup? Three tubs of bird seed represents 3# of breast weight.

I predict the cup volume of a 34D bra is less than the cup volume of a 48D bra.

That is a freakin' FABULOUS post!!!