Hello - I am wondering if anyone knows more about what this mark might be? It is on a heavy, chunky quite modern-looking necklace that I always assumed was just costume jewellery- but I have just noticed this mark on the back of three sections of the necklace. It looks to me like “K 84” - with a gap between the letter and number. Nothing else. When trying to do my own research all I came up with was that it could be a Russian(/Ukrainian) mark, and that K might stand for “Kiev” - but for some reason that just feels unlikely. I am attaching an image of the mark, and the necklace. Thank you!