Red to reddish brown powder.Odourless.
Insoluble in water, organic acids and organic solvents.Soluble in inorganic acids.There are two types, lust-type (positive
magnetism) and tow-type (diamagnetism).
Ordinary products produced by dry method have a fineness under 1 meters.
It is stable to light, heat and air.It is more stable to acid and base.Strong coloring.
Relative density 5.12 ~ 5.24.Low content means low density.Index of refraction 3.042.Melting point 1550℃, about 1560℃