Antique, Ornate Penannular Brooch, Silver with Gold Highlights, Amethyst Set Terminals

Antique, very ornate silver penannular brooch, with gold highlights, amethyst set terminals and a pearl set thumbpiece. Slightly flattened oval in shape with a pin extending top and bottom, applied gold decoration of bands and Celtic style half circles with 2 round faceted amethyst in the terminals and a pearl set within the thumb piece as adornment. Around 1.60 inch in both dimensions with the pin being 2 inches long. Marks on the pin, 1 is an initial and the other 2 are indecipherable, as it tests very close to 800/1000 silver I assume French and possibly Brittany in origin. Age; by style and type early 20th Century, I have had similar before dateable to that period. Cleaned for hygienic purposes only and quite toned but very pretty.