Effect of Iron Oxide on the Protective Photochromism of African Padauk

Table 2

Basic information of the red iron oxide.

Property	Transparent Red Iron Oxide
Molecular formula	α-Fe2O3
Molecular weight	159.69 g/mol
Appearance	Red powder
Melting point	1565°C
Boiling point	3414°C
Iron content	≥ 95% (m/m)
105°C Volatiles	≤ 1% (m/m)
Hydrotrope	≤ 0.3% (m/m)
Paste content	50%
Particle size	0.4 μm ~ 20 μm