Ferric ammonium citrate, also known as ferric ammonium citrate, has two kinds of brown and green. It has odorless, salty and iron smell. It is easy to absorb moisture. Because it can be reduced to ferrous salt by light, it is not even in solution state. Stable, easily soluble in water, insoluble in organic solvents such as ethanol and ether, the aqueous solution is neutral, green is easier to be reduced by light than brown. The brown scaly ammonium ferric citrate has a higher iron content, while the green scaly ferric ammonium citrate has a lower iron content.