Black powder. Insoluble in water, ethanol. Soluble in the method are dark green solution; In a green light black precipitation of hydrochloric acid; Sodium hydroxide solution in the blue; In a cold of sulfuric acid when dissolved, heating become dark green light blue precipitation, continue to heat into black and blue, green light blue after diluted produce precipitation. Dyeing objects in the alkaline solution is yellow powder insurance olivaceous, oxidation can restore the original colour and lustre after; Sodium hypochlorite solution in all fade.