With any successful fashion trend, there inevitably develops an industry specialising in the manufacture of like-items, copies and simulants.
It is a fact that some of these similar-looking materials were never intended to be confused with jet, but through a lack of consumer knowledge they are now often mistaken for jet, especially when passed down through generations as such. Other materials were nothing short of outright fakes, and without an expert knowledge of the real thing, it can be very difficult to tell the difference.
‘French Jet’ (Black Glass)
‘French Jet’ is the appealing Victorian name given to black glass. It is in no way connected to jet, nor is it necessarily from France. It was easily and cheaply produced in mass quantities using moulds, rather than the costly and time-consuming process of carving, as with real jet. French jet was rarely used to make ornaments, instead its use was restricted to jewellery, beads and buttons, the latter of which were manufactured in their millions. It was also used as decoration on materials, dresses, capes and other garments; hundreds of beads, sewn tightly together, shining with a bright vitreous lustre, would create a wonderful glittering effect by candlelight.
A type of very hard rubber, vulcanite was Whitby jet’s greatest competitor. The substance is a mixture of rubber with 30% sulphur that is then heated to 115°C.
It came onto the market as far back as 1845. The following year it was patented in the US by Charles Goodyear, who would later make his fortune by using the material in the production of car tyres. In the UK, vulcanite was patented in 1856 by Thomas Hancock, where it was mainly used in jewellery production. Vulcanite was the best imitation for jet because it was light in weight, warm to the touch and would even leave a ginger-brown streak when rubbed against sandpaper.
Horn is the natural by-product of an animal. Although it can be carved, it is a thermoplastic substance which lends itself well to the process of moulding. To make into jewellery, the horn would be heated, either in boiling water or by flame, before being put into a press and made into a brooch or pendant etc. Despite being moulded, no air bubbles can be seen in horn, although moulding lines may be visible when viewed through a loupe or magnifying glass. In its natural form, horn comes in shades of cream, beige and brown, so to create the deep black colour of jet, a dye was applied to its surface.
Bog oak is a semi-fossilised wood from no specific species of tree. It is formed in peat bogs, where a lack of oxygen prevents it from decaying as it normally would, and minerals contained within the peat react with the wood to create a much darker, tougher and denser material. Bog oak does not polish like jet and was never intended to imitate jet. During the Victorian era, it was a popular souvenir material in its own right. In 1882, 200 people were employed in the Irish bog oak industry, who were making jewellery and ornaments for sale to tourists.
Tortoiseshell should be quite easily distinguishable from jet by its colour, however, the darker varieties still cause some confusion as to its identification and it is therefore worthy of a mention. Tortoiseshell is an organic and translucent material that is both light in weight and warm to the touch. The name tortoiseshell is actually rather misleading as it is not a shell and not from a tortoise. It is in fact the overlapping plates, known as ‘scutes’ which cover the carapace (or upper shell) of certain species of marine turtles.
Cannel coal can look very similar to jet at first glance, but on closer inspection important differences are noticeable. Cannel coal is made up of very fine detritus and plant debris which have broken down and compacted under time and pressure creating a sapropelic coal that is not ‘jet black’ but a very dark grey that can also exhibit a metallic sheen, especially on broken surfaces. It does not take a good polish and at best has more of a satin finish which makes the material appear blacker.
First manufactured in France in 1855 by Francois Charles Lepage, Bois Durci was made from a peculiar mix of either ox’s blood or egg whites, with very fine saw dust, known as wood-flour. Although the wood-flour used was that of a dark coloured hardwood such as ebony or rose wood, the mixture was additionally stained with lamp-black to give it its very dark colour. Bois Durci was moulded into objects using heavy steel dyes, which were steam heated for about half an hour at between 150°C and 250°C, before being quenched in water.
Onyx is a variety of chalcedony which is one of a family of polycrystalline gemstones belonging to the mineral; quartz.
In comparison to jet, it is a tough gem material with a much greater hardness, almost all onyx is dyed to enhance its black colour and it is cut by a lapidary, rather than being moulded. As a loose stone, the most obvious difference between jet and onyx is its weight, onyx is much heavier than jet. Facet edges will also be much sharper than jet and onyx feels much colder to the touch.
Gutta percha is a type of rubber produced from the natural latex of Palaquium trees, native to Sumatra and Borneo. It was first introduced into Europe in 1656 by John Tradescant, head gardener to Charles I, who called it ‘Mazer Wood.’
Despite gutta percha being referred to again and again as a form of jet simulant, this is a very common misconception of the antique jewellery industry, and every example of ‘gutta percha’ jewellery the MoWJ has seen has in fact been another type of simulant, usually vulcanite.