antimony orange, antimony vermilion definition

Reddish/orangish paint pigments created with antimony trisulfide.  They were originally discovered and patented by Murock from Scotland.  In oil paint form they are bright, but in their dry state they are boring and dull to look at.  They are now obsolete, being replaced by cadmium reds in the 1920s.  Unfortunately, they had the nature of blackening when mixed with flake white and other lead pigments.