Appearance: blue crystal,

Assay98.0%, 
Fe:19.8%min, 

As:2 ppm max,
Cd:2ppm max, 
Pb:20ppm max,
Molecular Weight:278.05,

Insoluble matter: 0.2%max

Molecular Formula: FeSO4.7H2O,



Applicant:
Nutritional supplement
Together with other iron compounds, ferrous sulfate is used to fortify foods and to treat iron-deficiency anemia. Constipation is a frequent and uncomfortable side effect associated with the administration of oral iron supplements. Stool softeners often are prescribed to prevent constipation.

 Colorant
Ferrous sulfate was used in the manufacture of inks, most notably iron gall ink, which was used from the middle ages until the end of the eighteenth century. It also finds use in wool dyeing as a mordant. Harewood, a material used in marquetry and parquetry since the 17th century, is also made using ferrous sulfate.

Two different methods for the direct application of indigo dye were developed in England in the eighteenth century and remained in use well into the nineteenth century. One of these, known as china blue, involved iron(II) sulfate. After printing an insoluble form of indigo onto the fabric, the indigo was reduced to leuco-indigo in a sequence of baths of ferrous sulfate (with reoxidation to indigo in air between immersions). The china blue process could make sharp designs, but it could not produce the dark hues of other methods. Sometimes, it is included in canned black olives as an artificial colorant.

Ferrous sulfate can also be used to stain concrete and some limestones and sandstones a yellowish rust color.Woodworkers use ferrous sulfate solutions to color maple wood a silvery hue.

Other uses
In horticulture it is used for treating iron chlorosis. Although not as rapid-acting as iron chelate, its effects are longer-lasting. It can be mixed with compost and dug into to the soil to create a store which can last for years.[4] It is also used as a lawn conditioner,and moss killer.
In the second half of the 19th century, ferrous sulfate was also used as a photographic developer for collodion process images.