The production process of blue cobalt is special. by adding " " (the main component is cobalt metaaluminate: Co(AlO2)2) in the production process. The addition of gave the , so it was named blue cobalt . Features - Size: 5.00X5.00X0.50cm/1.97X1.97X0.20in - Material: . - The elements corresponding to the cobalt elements makes it powerless to absorb blue light (that is, it reflects or transmits blue light, and for yellow light with different blue wavelengths, cobalt elements can completely absorb). - Blue cobalt has cobalt , so cobalt can yellow light. - In industry, in the field of cement production, in order to have a good grasp of the production situation, it is also necessary to observe the flame through cobalt . - The excellent workmanship of our product will bring you a . - It is lightweight for easy and convenient to carry and store when not in use. Package list: 2 x glass sheets