Is there any way to retrieve an expensive earring that has fallen down a porcelain sink? The sink is porcelain all the way to the floor, and it's on the second floor bathroom. I think if I don't run the water, that I may be able to see it if the water evaporates, because there is some kind of block there that always seems to hold some water, while the rest of the water drains through a hole on the side of the pipe to the main drain. I think the sink is from the late 70s, early 80s, if that makes any difference. We've got pipes in the basement, and they lead to a septic tank. Sorry if this doesn't make sense, and thanks for reading my question and replying if you do reply.

First don't run any water in that sink.
That "some kind of block" is the sink trap. It is there for a reason. The earring should be in the trap if you have not run much water.
Depending on what the earring is made of, you may be able to get it with a magnetic pick up tool. Relatively inexpensive tool from automotive store. Another approach would be to vacuum it out with a shop vac. Clean inside the shop vac and put panty hose over the hose inside the vacuum so you can find it when you vacuum it out.

You have the other earring, right. See that rubber seal around the your refrigerator door. There is a magnet inside that seal. Hold the other earring next to it to see if it is attracted to it. If so, you can probably get the earring out of the drain with the magnetic pick up tool.

If the magnet or the shop vac doesn't work call a plumber or a handyman.

Thanks for your reply, I forgot to mention that it isn't magnetic. My neighbor has a shop vac, so I may be able to borrow it. Thanks, I won't run any water in that sink, and I'll hope for the best with the shop vac. After I posted it, I thought of seeing if the local hardware store had any extra long tweezers, or tools of that sort. Thanks again for your reply.