Jet semiprecious gemstone index and mineral information

Jet is a hard gem variety of lignite (a type of coal), which is often carved or faceted, and takes a good polish. Jet has high carbon content and a layered structure. It is black to dark brown, and sometimes contains tiny inclusions of pyrite, which have a metallic luster. Jet’s name derives from the Old French jyet or jaiet after a place on the Mediterranean coast where the Romans obtained some of their jet. Jet is the fossilized wood of prehistoric trees that have been compressed over millions of years. It smells like coal when burnt. Some jet may induce electricity when rubbed, and for this reason it is sometimes known as “black amber.”

Jet was a very popular gemstone during the Victorian era when it was used as mourning jewelry. After the death of Queen Victoria’s husband, Prince Albert in 1861, Queen Victoria went into a forty year period of mourning. Jet from Whitby in northern England was used extensively. Whitby was famous at the time for the mining and crafting of jet, and this industry was responsible for most of town‘s income during that time. Jet has been used in jewelry since ancient times and was made traditionally into rosaries for monks. In medieval times, powdered jet drunk in water or wine was believed to have medicinal properties. In India, jet amulets were believed to protect the wearer against the evil eye, and Irish women traditionally burned jet to ensure the safety of their husbands when away from home.

Today jet is found in Whitby, England, Spain, France, Germany, Poland, India, Turkey, Russia, and the United States.

Jet can be confused with anthracite, asphalt, cannel coal, onyx, and schorl. Some imitations are made with glass, vulcanite and plastics.