The crystal sphere observator is a tool for observing iridescent concentric circles on the surface of the crystal sphere using polarizing filters. You can also distinguish glass balls and crystal balls that are difficult to tell with the naked eye.
Place the crystal bulb between two straight polarizers (cross nicol) which are straight with the polarizing axis and illuminate with the fluorescent light to observe the concentric circle of the rainbow color. You will not be able to see this concentric circle unless you have a real crystal ball. As a geographical material, you can check the bi-refractive and luminous properties of the crystal.
In addition, when you change the filter on the observer side to a circular polarizer, the rainbow concentric circle will change to a left or right hand spiral pattern. Natural crystal grows like a spiral on the right-hand or left wound spiral.
A popular geography material that combines a stage for placing crystal balls and 3 optical filters in a compact case.
It can also be used for certification of crystal bulbs, but we are not responsible for any damage to your property