I recently saw for sale a silver 3d with a small hole bored through just above Victoria's head, which makes me think it was once worn on a neckchain or bracelet. ( Shame to do this to such a nice coin !).
Apparently wearing coins as jewellery is not new. I recently read that in mediaeval Venice, Italy, Zecchins were sometimes worn on women's clohing, from which we get our word "sequin".