I am trying to figure out What country of origin marks KT 18, vs. 18K on my ring!?

Thank you for the previous answers! I am sorry I wasn't more clear about my question, so what I'm trying to figure out, is there a particular country that marks 18k gold jewelry, KT 18. I've never seen a piece marked like that before, so I'm wondering if it being marked the way it is, that this denotes a place of origin? Since I cant' load a picture, I have this 18k ring/aquamarine stone on my website that has all photos, if anyone can check it out and let me know. It's www.iamvintage.net, so if you could provide some assistance as to what country or maker since I've been researching for over 2 weeks now, I'd be grateful!