Selenite is a popular crystal for a reason. There are several variations of Gypsum known as Selenite, these slabs are the clear kind.
Each slab is between 4-5 inches long and 3-4 inches across at their widest points. Selenite is incredibly fragile so be mindful and do not get wet.
Selenite is a universal charger; it can cleanse and recharge any other Crystal without needing to be cleansed or recharged itself. Place your stones, jewelry, or anything else you want infused on top of or by the slab and let Selenite do what it do.