Clear Quartz is considered a "master healer" & multipurpose/multidimensional stone that is perfect for the beginner. Some of it's uses are intuitive development, psychic sight, healing, meditation, wisdom keeper and lots more. Each one has a rainbow inclusion in it that shines of hidden joy, optimism, and understanding. The light reflection that creates the rainbow usually comes from ancient rock crystals which allowed water and other minerals to flow inside the crystal's interior. When light hits this inclusion, it's also reflected back from both sides.These are around 1" to 2".