Soluble in water, aqueous solution is red to bluish red, solubility in water is 15g/L (60℃), 24g/L (97℃), very sensitive to hard water. Adding concentrated hydrochloric acid in aqueous solution produces bluish green precipitate; adding concentrated sodium hydroxide solution shows yellowish orange color. Slightly soluble in ethylene glycol ether, insoluble in other organic solvents. Blue in concentrated sulfuric acid, purple after dilution; blue-black solution in concentrated nitric acid, then blue, finally olive. When stained with copper and iron ions, the color and light change slightly.
