dark green to dark brown or black powder.
Praseodymium oxide is a weak coloring oxide that melts at (1710°F)932°C. One of the lanthanide oxides, praseodymium is classified in the periodic table as a rare earth oxide. It's not used extensively in ceramics but is used in yellow stains with zirconium silicate. This oxide is slightly soluble in water and is very toxic.
Praseodymium can be obtained as an oxide but it's usually introduced into a glaze recipe in the form of a commercial stain such as Mason 6433,6405, or 6407.