What is iron sulphate at room temperature?

At room temperature, iron(II) sulfate, commonly known as ferrous sulfate, is typically a crystalline solid with a pale green or blue-green color. It is hygroscopic, meaning it can absorb moisture from the air, and is often found in a heptahydrate form (FeSO₄·7H₂O), which contains seven water molecules. Iron(III) sulfate, on the other hand, appears as a yellowish solid and is also stable at room temperature. Both compounds are used in various applications, including agriculture, water treatment, and as a laboratory reagent.