PD on a hoop normally signifies palladium. Your ring might be palladium-plated if it's PD written about it. HK is actually a trademark that means Harriet Kelsall. They style and supply jewellery all over the UK and also to other sites too.  Can “JP” also stand for another nation? Even https://garrettxxunf.blogmazing.com/36039609/the-smart-trick-of-jp88-that-nobody-is-discussing