It is an excellent synthetic substitute for Calcite(CaCO3) and Rutile(TiO2)
crystals in many applications including fiber optic isolators and Circulators, beam displacers,
Glan polarizers and other polarizing optics, etc.
To troubleshoot the Circulator pump, you will first need to make
sure that the boiler is already hot(if not, it is a thermostat problem), but the hot water is not being moved out of the tank.