Vintage Modernist Amethyst Solitaire & 9k Gold Ring Size K 1/2. Made by the excellent P & R Bushell. It is fully hallmarked for 9ct gold with the crown, "375", the Birmingham assay mark, the makers mark "P&RB" for P & R Bushell and date letter. It weighs a substantial 2.3 grams. It is a size K 1/2. Excellent condition.