Some old coins=one is a Roman coin with a figure of Constantine on it. An 1816 penny from one of the colonies in the Caribbean. I had a custom Vaquero made and de-constructed an El Paso Saddlery belt and used original Indian Head pennies for conchos.
Well, There is a 1905 Liberty Head Nickel I've owned since selling news papers as a kid on a Navy Base; The other is a Win 94 30-30 Saddle Carbine from 1927 that belonged to my GrandFather. Does being 81 + years old count for anything?
Forgot about fossils. I have one from the construction of the Getty Museum in Los Angeles maybe 20 years ago. It's in a piece of what the stonemason, a client working on the project, called "Coliseum stone" and came from the same quarry the Roman Coliseum materials did. He said it was from an ancient sea and was pretty young--maybe 10,000 yrs old.
Otherwise a couple of books dating to the late 1800's and maybe a Morgan dollar sitting in the bottom of the sock drawer are it for me.