What a stunner! This is a bespoke antique 9ct gold amethyst extender pendant, made from antique and vintage components. It features a large east to west 2ct bezel-set amethyst with a rope twist border attached to a buttery 9ct gold dog clip which measures 20x7mm.
See how wonderful it looks styled in the pictures above with an Albert chain. It weighs 3.9g, measures 5x1.3cm, is unmarked but XRF tests for 9ct gold.