A stone which has been shaped and polished without faceting, the word cabochon, sometimes shortened to ‘cab’, derives from the French word caboche meaning dome or knob. Before faceting began in the late 13th century, most gemstones were turned into cabochons. Certain stones are better as cabochons than faceted stones – for example, if the stone has a particular optical features – chatoyancy (cats eye), asterism (stars), iridescence, adularescence. Lower quality precious stones (including some sapphires, rubies and garnets) are sometimes shaped into cabochons where the clarity is not good enough for faceting, as are softer stones, since scratches are not so visible on a rounded stone.