You use another crystal for protection, clear quartz will amplify its energy and manifest even more protection into your life. Used on its own, clear quartz cleanses energy, meaning that you can use it to release anything that is no longer serving you.
Green aventurine declutters the energy field, especially around the heart chakra. This is why it is a wonderful stone for attracting romance. It assists us in healing old emotional wounds while simultaneously opening us up to receive more love.