A pyramidion (plural pyramidia) is the uppermost piece or capstone of an Egyptian pyramid or obelisk  in archaeological parlance. They were called benbenet in the Ancient Egyptian language, which associated the pyramid as a whole with the sacred benben stone. In Egypt's Old Kingdom, pyramidia were generally made of diorite, granite, or fine limestone, which were then covered in gold or electrum; during the Middle Kingdom and through the end of the pyramid-building era, they were built from granite. A pyramidion was "covered in gold leaf to reflect the rays of the sun"; during Egypt's Middle Kingdom, they were often "inscribed with royal titles and religious symbols."