These are perfectly polished flat black obsidian mirrors. I have two sizes available. You can choose from 3 in or 5-in. Obsidian is black volcanic glass. It's the sharpest material that we know and is sometimes used to make tools. Because of its deep darkness, It has also been used in protection, magic, and divination. It is said that you can use this mirror to gaze into and enter meditative state in which you are able to receive messages from spirits. There is a long history of magical folks using obsidian in their practices.
Like all magical tools, it is just that, a tool. The magic is within you and the universe, but these beautiful pieces can ate us in our workings.