Iron Sulfate (FeSO₄)
Iron sulfate (FeSO₄), also known as green vitriol, is a chemical compound that plays multiple roles in ceramics due to its decorative and functional properties. In decorative ceramics, it is mainly used as a colorant to generate warm tones, such as yellows, oranges and browns, as well as to create speckled or textured effects in glazes and engobes. These effects are especially appreciated in artistic pieces that seek a natural and rustic aesthetic.
Iron sulfate is a reactive material that interacts with other oxides and components in the ceramic mixture, generating unique patterns and textures during firing. In oxidizing atmospheres, it stands out for producing brighter and more defined tones, while in reducing atmospheres it can generate darker and duller colors. In addition, iron sulfate is used in decorative techniques such as splattering or direct painting on the surface of the pieces.
In technical applications, iron sulfate can act as a chemical modifier in high-temperature glazes, helping to stabilize mixtures and prevent cracking. Its use requires careful planning, as its concentration can significantly influence the final results.Interesting Fact
The use of iron sulfate in ceramics dates back to ancient times, when the Egyptian and Roman civilizations used it as a natural pigment to decorate terracotta vessels and utensils.Helpful Tip
Start working with low concentrations of iron sulfate to prevent dark tones from dominating the piece. Mix the material well and sift it before applying to ensure even distribution. Work in a ventilated space and wear gloves and a mask to protect yourself from the dust, which can be irritating.
