A friend once told me that modern wedding rings started as a symbol of slave ownership. The master would put a ring on the slave's finger to identify him as his property. Later, the ring became a way for husbands to show "ownership" of their wives, and then in modern times both partners used rings because husbands and wives were equal. I've found various pages that claim to prove or disprove this (eg., this Yahoo Answers thread: https://answers.yahoo.com/question/index?qid=20071113105407AAG1lx1), but they aren't scholarly or reliable sources. Is there any truth to this rumor, and if not, where did wedding rings really come from?
Wedding rings go back to antiquity, one of Pliny's most famous passages, his discussion of rings, mentions wedding rings. We have lots of references to wedding bands, and Gellius famously mentions the belief that they are worn on the second-smallest finger because from that finger there is a nerve (nervus can technically mean a nerve or a sinew or even a muscle of vein--presumably Gellius means an actual nerve) that goes straight to the heart. Gellius here says he's quoting Apion, and claims that this practice goes back to Egyptian dissections and was adopted by the Greeks from them, though surely this is fancy. Wedding rings simply predate American slavery by several millennia, and they cannot have been used among Roman slaves, as the right to wear a ring was the right only of a free man
EDIT: So I phrased that poorly. By the second-smallest finger I mean the ring finger, the finger next to the smallest finger of your hand (which should be your pinky unless something is very wrong with my own hands).