摘要:
Magnesium fluoride particles with a low refractive index excellent in film formability are provided. The magnesium fluoride particles each include at least one magnesium fluoride particulate. The at least one magnesium fluoride particulate each has pores that support a supported substance. Further, the at least one magnesium fluoride particulate includes a plurality of particulates. A grain boundary void-like pore serving as a gap that supports the supported substance is present between particulates adjacent to each other of the plurality of particulates.