Zinc silicate is a mineral and ore of zinc which has a number of industrial uses. It is also known as hemimorphite, and is sometimes referred to by the antiquated name “calamine,” which actually can refer to zinc silicate or zinc oxide, two minerals which can be hard to distinguish without inspection. This mineral is blue to green in color, with a crystalline structure, and can be found in natural deposits in several areas of the world. In addition to being used on its own, it may also be treated to extract the zinc it contains.
This mineral is transparent, although it can be rendered murky by the presence of impurities. Some regions contain large known deposits of this mineral, including Germany, Thailand, Belgium, parts of the United States, Poland, Siberia, and Austria. Zinc silicate may be mined and treated in these regions, and it can also be mined and shipped in raw form to other locations for processing.
Historically, zinc silicate was used as a food additive, added as an anticaking agents to some types of foods, but this use is relatively rare today. Another application in which it continues to be widely used is in the manufacture of products which need green phosphor, such as fluorescent lamps and display tubes. In this case, it is doped with other minerals, and it can be rendered hazardous to handle by the doping agent.
This mineral is also widely used in coatings which are designed to inhibit corrosion. Zinc silicate can be used in corrosion inhibitors such as those applied to ships, buildings, and certain types of vehicles. The mineral acts to help protect the underlying surface from corrosion, extending its lifetime. Anti-corrosive coatings are especially important when something is being used in settings where corrosion is likely; oceangoing boats, for example, are prone to damage from the saltwater they sail through. It may be known as “inorganic zinc silicate primer” when it is used in these settings.
Exposure to this mineral is not necessarily harmful, although excess zinc intake can cause health effects. In fact, zinc is a necessary dietary mineral which many people absorb in adequate amounts by eating a balanced diet. Too much zinc can interfere with the absorption of other dietary minerals. Individual products made with this mineral may be harmful because of additives used during manufacturing; products which are dangerous may carry warning labels to familiarize people with the precautions associated with the product.