Shop SILVER PEBBLE - SUGARLOAF & CUSHION6mm Silver Amethyst Sugar loaf ring. 128-SIL-AM 6mm Silver Amethyst Sugar loaf ring. 128-SIL-AM € 295.00 6mm Silver cabochon Amethyst Sugar loaf pebble ring. Finger Size N - other sizes available. This beautiful cabochon sugarloaf gemstone measures 6mm x 6mm approximately.