Also referred to as Iron Chromate
A dense compound of iron and chromium. It is very refractory in oxidation, even with 50% borax and zero-alumina Ferro frit 3134 it does not melt. It is used in glazes to produce gray (with feldspar), brown (with zinc), red (with tin) or black depending on the base glaze and percentage and other coloring oxides present. Often used in underglazes, engobes and clay bodies.
Highly toxic in absorption, inhalation, and ingestion.