Copper(II) nitrate, Cu(NO3)2, is an inorganic compound that forms a blue crystalline solid. Anhydrous copper nitrate forms deep blue-green crystals and sublimes in a vacuum at 150-200 °C. Copper nitrate also occurs as five different hydrates, the most common ones being the trihydrate and hexahydrate. These materials are more commonly encountered in commerce than in the laboratory.
Copper nitrate is used as a mordant and oxidizing agent in textile dyeing. It is used as a pigment for glass, enamels, and ceramics. Because of its toxicity, it is also used as a fungicide, and wood preservative