This design is reworked from an ancient brooch thought to be of either Germanic or Viking origin from Medieval times. I have added a few details that looked to be missing as well as a Celtic knot outer border. The colours represent different shades of amethyst stones and lapis lazuli, known to be used in jewellery of this type from this period.
I have painted the design in Sakura gold powder with gum arabic binder and watercolour gouache on hot-press watercolour paper.
The image size is 156mm in diameter.