Vermilion (SHU) from Nishidani Historic Site of Yayoi age is natural cinnabar (HgS), lighter orange red to purple red in color.
In order to solve the question of color tone of vermilion from Nishidani Historic Site, detailed studies were carried out on these samples, by means of chemical analysis by EPMA and observation under the electron microscope.
The results leads to the followisg conclusions that characteristic differences of color tone were occured by grain size of crystal of cinnabar.