What symbol is on a rosary?

The only symbol ever truly associated with the Order of Illuminati was the Owl of Minerva. It represented then wisdom and knowledge, much the same today, over two hundred years since the Illuminati was disbanded. As the Catholic Bishop of Nuremberberg was instrumental in the demise of the Order, and the Order espoused severing governmental ties with the Church, it is highly unlikely the Order would have used such a staunchly Catholic symbol such as the rosary as a symbol.