So what do we know? It's a crafted object, not extant in the First Age but around in the Third. It's small enough and light enough to pick up. It's almost certainly not a weapon - not a sword, not one of the Hobbits' knives, and not a bow or arrow (which would be wooden). It's not made by Feanor, which rules out... the Palantiri, I guess. It's not a jewel, so isn't the Arkenstone (the Elessar was already out by virtue of its name; it's kind of a shame this question didn't say 'jewellery', to get the Rings as well).
It doesn't have an Elvish name, which rules out a lot. While it could be the One Ring, most other things without Elvish names are 'regular use' items. So... hmm.
If it's not wooden, it could be metal, stone, or some form of organic material - cloth, food, paper, something like that. Metal would probably point to a Ring; it could be something like Pippin's brooch, but that would surely be a 'Hobbit thing'. It could also be armour. Stone... you know, I actually can't think of a liftable stone object that isn't already ruled out. Organics could be anything from the Book of Mazarbul to Denethor's dinner. (It could also be Aragorn's standard, but we're going to know that explicitly pretty soon.
)
I like to think in terms of splitting the field in half, rather than trying to rule out specific answers. There's only a few metal answers still viable, only a few stone ones (if any), and not a whole lot of animal-based material ones. Add them together, and they probably equal the plant-based answers, and therefore:
-Is it made of a material that came from plants?
hS