Oh... I loved this poem, sorry I missed it when you posted it!
I liked the repetition, it worked really well and I was really getting involved with the poem by thinking of my own ring and how much it means to me, but then how little it would mean to someone else if they had found it.
The poem was taking shape nicely, and I had no idea you were then relating it to the film of "Lord of the rings" until I read about the 3rd and 4th stanzas where I was a little confused, but then after reading your footnote about the prompt of your poem, it makes more sense now.
I do not think you need to worry about the poem being copy righted, you only used the film as a prompt. (now as long as you do not act out the plat with actors and reproduce the film!Lol)
The po3m was great, and it held a lot of meaning over possessions and how priceless, yet powerful they can be to the right people.