Fun and unusual earrings of Whitby jet with a jet ball hanging below carved Whitby jet florets. Whitby Jet is fossilized coal mined in Whitby, England in the 19th century and made into jet jewelry, used at the time for to create jewelry. It was truly a cottage industry, with men extracting the jet from the mines and turning the precious material over to woodworkers, who hand turned and carved the jet into smooth forms. The jewelry would then go to the women to polish, finish, and assemble the pieces. The jet industry kept many a worker gainfully employed for the better part of the 19th century as the demand for mourning jewelry created a thriving industry. The last jet woodworker finally retired in the early 1900's, and signaling the end of the Jet jewelry production. What littleJet jewelry exists today is all that is left and is truly a collector's item.