Jet is a type of coal, the product of driftwood that eventually gets waterlogged, sinks to the sea floor, is slowly buried in mud, and hardens over millions of years. Unlike coal that’s used for fuel, jet forms in salt water rather than on land.
Though closely associated with the mourning jewelry of the Victorian Era, jet has been used in all sorts of jewelry for perhaps 10,000 years. According to Hayden Peters, the ancient remains of jet amulets and beads have been found in present-day France and Germany. More recent examples, only 4,500 years old, have been unearthed in the United Kingdom, from Yorkshire to Scotland. The jet used in those pieces was probably mined in what is now North York Moors National Park, which is just inland from the seaside city of Whitby, which has long been a center of jet-jewelry production.
The use of jet really took off, if you will, in the middle of the 19th century, when two unrelated events propelled it to newfound popularity. The first was the Great Exhibition of 1851, held at the Crystal Palace in London’s Hyde Park. Among the exhibitors there was Isaac Greenbury, one of Whitby’s most acclaimed jet carvers. By 1854, Greenbury had received orders from the Queen of Bavaria for a jet chain in excess of 6 feet in length, as well as a pair of bracelets from the Empress of France.
This sort of royal patronage on the continent gave the material instant cachet, but England’s Queen Victoria already had a designated “jet ornament manufacturer,” Thomas Andrews of London. When the Queen’s husband, Prince Albert, died at the young age of 42 in 1861, his royal wife went into mourning for the next 40 years, only wearing jet for adornment, and decreeing that those in her court do the same.
The impact on Whitby of Albert death and Victoria's penchant for all things black was profound. In 1832, for example, there were only two jet manufacturers in the small town, providing work for only a couple of dozen carvers. By 1872, 1,500 people, many of them children, were toiling in some 200 shops, carving cameos, pendants, and beads. While some carvers attempted to keep up with demand by importing jet from Spain and France, Whitby jet was more desirable because it was harder, producing sharper, more detailed designs. It was also less prone to cracking, which is why the softer imported jet was relegated mostly to beads rather than finer pieces.
Beyond jet, other black or dark materials were used in jewelry, too. Black glass, of course, but also a hard rubber called vulcanite, as well as bog oak, which is similar to jet in composition but has a browner hue. In terms of semi-precious stones, the go-to mineral is onyx.