It looks similar to the stretch bracelet that Gucci and Tiffany’s sold, or may still sell. The ones I’ve seen have little metal pieces in between each bead so it isn’t on elastic but rather a chain which is covered by the metal pieces. Sorry, it is difficult to explain. Very sturdy, but I doubt it is resizable and if so, not easily and definitely not inexpensively.
Thank you, tbbjb!!! It sounds very much like you are describing! When I stretch the bracelet, no elastic is seen, just smaller pieces of gold that seem to act as springs beneath the little gold balls. It’s extremely hard to explain. Maybe I can get a photo that might show it better. But I think you are right and trying to resize it in any way would either be disastrous or prohibitively expensive... or both! Lol.