> I suppose that poll question was about man-made objects. If so, my arrowheads would count, but a piece of unworked flint from the same deposit would not.

My answer may have been not quite what was intended in the poll question. I have some large thundereggs from the mountain I grew up on, which hasn't been anywhere near volcanic activity in way more than 1500 years.

Counting only manmade objects, the oldest I own is probably 80-100 years.

-Gabe