This is a Dragon Tooth Amethyst Point, also goes by "Dragon Club". This particular variety of amethyst only comes from the Bahia region in Brazil. It's shape is described by the short tip and long root which gives it that "tooth" appearance.
They come in three different sizes, small, medium, and large. Not all of the large ones are double terminated.
You will receive one in the size of your choosing, similar to the ones pictured.