Tellurium. Tellurium is a model used to demonstrate the movement of the earth and the moon around the sun. This attractive and captivating material is a simplified reproduction of the solar system. Tellurium is not a replica of the reality, but a model to explain the different principles of day and night, summer and winter and the positions of the moon. Tellurium visualizes to the children, the fascinating effects created by the rotational movements in our sun-earth-moon system.