The heart is a popular cut for Selenite, they are great for meditating as they fit nicely in the palm of your hand. They measure between 2" and 2 1/2" wide.
Selenite calms, brings deep inner peace, and offers access to past and future lives. It helps bring mental clarity, clearing confusion and revealing the bigger picture behind problems so it is a wonderful stone to meditate with. It is also a very protective stone, it will shield you from outside influences.