I'm no expert on late Roman-early Byzantine bronze weights to say the least, but I am rather obsessed with this one, finding it a wonderfully mysterious, miraculous, and beautiful tiny thing. I purchased it from a favorite shop (very beautiful itself) in Vermont, where one of the two owners s himself obsessed and quite knowledge about these sorts of things. I haven't dug very deep, but from what I understand small bronze weights like this were used as coin weights, and it seems sometimes jewelers weights as well, with some of them having a faceted  form as this one does, with decorated sides, I believe relating to their weights. The finer details of this one require magnification to see (on first sight--and what attracted me to it originally--it looks like a tiny, beautiful green, many sided die, as in dice.) A closer look reveals different patterns and size/scale of marks carved on each side, with clear intentionality and specificity, and one side with a larger round inlay at center, shining gold (and seems possible it is.) I'm quite content just to marvel at it, and at its age too--c. 6th-8th century AD I believe.

Approx 3/8" x 5/16". Beautiful condition. Shipped in the little padded case I purchased it in.