Then if all the matter in the universe originates from plasma, which is cooling, and most of the matter in the universe cannot be observed by current astronomical means, but its anisotropy in the universe, is known and its effect of lens in outer space. Now knowing the characteristics of the crystals, which are very difficult to observe them with current astronomical means, its characteristic of anisotropy and its nature of lens effect, it can be concluded that dark matter is an ionic crystal.