This beautiful stone is a type of gypsum called SELENITE... the name comes from the Greek word Selene, meaning moon. In past history, due to it's transparency, it has been used for window panes, such as those in Santa Sabina in Rome. Selenite is a stone of love and harmony. Personally, selenite is my most favorite type of stone. I love the reflective beauty as well as it's energy. The pieces that we have at the shop are similar to the size of a bar of soap. Wonderful to hold in the palm of your hand.