Chromium Sesquioxide CAS #1308-38-9

Chromium trioxide is one of the ten most abundant compounds in the Earth’s crust. It is one of the four chromium oxides with the chemical formula Cr2O3. When used as a pigment, it is often called “chrome green”; however, when it was first discovered, it was called “chrome green”.
Chromium trioxide is a very refractory ceramic colorant (even a 50% mix with high borax frit will not begin to melt it in a crucible). Chromium oxide is the only stable oxide of metallic chromium. It is a bright green to dark green crystalline powder that is insoluble in alkalis and acids. It is made from chromite ore mined in southern Africa, Asia, Turkey, and Cuba. Like other strong colorants, chromium must be ground finely enough to eliminate specks in glass or glazes.