| ||Guide to Jet Jewellery|
Click on the link above to download the free guide in pdf format.
The guide gives information on Whitby Jet and the materials used to imitate it. It also provides information on how to take care of your Jet items and an indication of how much your item might be worth.
Updated for 2009.
About Whitby Jet and its Simulants Jet is fossilized wood formed from a species of Araucaria (the monkey puzzle tree). It is synonymous with the colour black and can be highly polished to give an intense black colour that never fades. When polished the material is so reflective that pieces of Jet were even used as mirrors in medieval times. It is a tough material but lacks hardness, which makes it easy to carve but also easily scratched and damaged.
Jet is found in small deposits around the world, in countries including the UK, France, Germany, Spain and the USA. Deposits vary in quality from region to region, largely dependent on the levels of trace elements such as aluminium, silicon and sulphur. Deposits from around Whitby in North Yorkshire have high levels of aluminium and this produces Jet of extremely high quality.
|Jet has been used in the manufacture of jewellery and tokens since the bronze age. Since that time a wide range of items have been made from the material; from Roman medallions to Victorian mourning rings and on to the modern silver and Jet items popular today. After a long history, Whitby Jet is once again the jewellery of choice and none more so than the original Victorian pieces.|
Whitby Jet was much favoured by the Victorians as a material for the manufacture of beautiful jewellery. With its light weight, deep black lustre and warm touch to the skin it was both practical and elegant. But the passion for Jet has often outstripped the capacity of the natural reserves and spawned many imitators.
Imitators and Simulants
Anthracite is found in many places around the world and is a compact and brittle carbon material. Less durable than Jet it polishes well but has not been extensively used for jewellery. Miners were known to fashion small ornaments and carvings from it, mainly as a hobby.
It has a glassy metallic look, distinct from the soft lustre of Jet, and will leave a black mark when rubbed against a piece of fine abrasive paper or unglazed porcelain. If burnt it produces a blue flame and very little smoke.
Bakelite is a phenolic resin, patented in 1909, and was the first truly synthetic plastic material. In weight it is about the same as Jet and it has a deep black colour and can be polished to a good finish. Bakelite was used in the manufacture of brooches, bracelets and beads and can be moulded when heated. It is more durable than jet and can appear too perfect when compared to an antique Jet item with its common collection of chips and small cracks.
When scratched Bakelite produces a black powder. But a more obvious giveaway is that many Bakelite items will be stamped on the reverse with the word 'patent'.
This material is a hard black semi-fossilized wood originating from the peat bogs of Ireland. A very popular material with the Victorians it has been used to make items both large and small. When George IV visited Ireland in 1821 he was presented with a walking stick made from the material. Small jewellery items usually have typically Irish designs and decoration. Some later pieces had the designs stamped onto them rather than carved.
Bog Oak is dark brown in colour rather than black and does not polish as well as Jet or some of the other simulants. Often it will have a distinctive peaty smell.
A material patented in France and consisting of fine sawdust or wood-flour mixed with albumen and stained with lamp black. Used in the limited manufacture of jewellery between 1850 and 1880. The material was not very durable and few items survive.
Cannel coal or 'candle coal' as it is sometimes known is not as black as Jet and under certain conditions can appear to have a silvery grey sheen. Seldom used for jewellery it was mainly used in the production of small sculptures, ornaments and items such as snuff boxes. Cannel coal will burn more easily than Jet and with less smoke.
Black Enamel is sometimes found on brooches, lockets and rings. It is significantly harder than Jet and unlike Jet it cannot be scratched with a pin.
This is the latest plastic to be used in the reproduction of Jet jewellery. Often the reverse side of these items will be slightly concave due to the shrinkage that occurs as the material sets.
When scratched most epoxy resin items give a black powder and when heated the material produces a smell of carbolic.
Black glass, or 'French Jet', is one of the most common materials used to simulate Jet items and was used extensively to produce necklaces. The glass was generally moulded and produced a cheaper alternative to the hand carved and polished Jet.
A limited amount of black glass jewellery was also produced in England where it was known as Vauxhall glass. When held to the to the light it has a slightly reddish or purplish tinge as a result of being coloured with manganese oxide.
Black glass is easy to tell apart from Jet as it is heavier and colder to the touch. It also has a bright shine and hard appearance, unless it has been intentionally dulled or 'bloomed'.
Horn is light and can be easily worked, even moulded if heated in water. When stained it can be passed off as Jet but items are often rough and scaly on the reverse side.
Horn does not have the deep glossy black of Jet and when held up to the light the edges are often translucent due to incomplete staining. When scratched the material produces a grey powder. When a hot needle is applied the material will smell of burning hair.
Lignite is another form of coal deposit that is not as dense as Jet. In Germany its use predates that of Jet, whilst in Britain it can be found alongside Jet in the remains of Roman settlements.
Few items have survived the centuries without cracking or breaking up and it was little used after Roman times.
Onyx and Chalcedony are two forms of quartz that occur in black, or can be stained black. Onyx was frequently used by the Victorians for Jewellery items but like black glass it is easy to distinguish from Jet by its weight and cold feel.
Kimmeridge shale is a bituminous shale found in Dorset in the south of England. In its natural state it has the appearance of slate. It is light and ranges in colour from grey-black to brownish-black.
When polished it looks very similar to Jet but tends not to retain its lustre over time and items often crack or break due to the gradual loss of its natural oil content. The material was used from the Iron Age to the end of the Roman occupation.
In 1846 a patent was taken out for a material made by mixing rubber with sulphur and then heating it to 115 degrees C. The resulting hard material known as Vulcanite or Ebonite turned out to be the most successful simulant of Jet.
It was light, black, could be polished and like glass could be moulded to mass produce items quickly and cheaply. Items such a brooches, pendants and chains were all made from the material and often Jet and Vulcanite items can be found in near identical designs.
Like Jet, Vulcanite produces a brown powder when scratched. It does give off a faint sulphur smell but this is almost impossible to detect. Vulcanite is more durable than Jet and therefore unlikely to chip or crack. As with Bakelite this can be an indicator that the item is not a genuine antique Jet piece.
When Vulcanite is directly compared with genuine Jet it appears less black. If the material has been exposed to light for long periods then the item will usually have faded to brown. When burnt it gives off a strong smell of burning rubber.
Some cheap jewellery was made using dark woods such as ebony or by staining lighter woods or painting them with black enamel paint. On older items the finish is likely to be scratched or worn, revealing the natural wood beneath.
More About Whitby Jet For more information about Jet and its simulants we recommend two excellent books:
Jet by Helen Muller.
The book is £12.00 plus postage £1.50 UK, £5 worldwide.
Brand new (colour fronted) black and white copy of the original publication "JET" by HELEN MULLER. The first and only large book ever written on WHITBY JET, covering its history, geology and simulants e.g. VULCANITE, BOG OAK etc. 149 pages lavishley illustrated, find out what is real WHITBY JET and what are its immitations. Buyer can request any signing of the book by the author.
Copies of the book can be obtained by contacting Helen Muller's daughter Katy:
Whitby Jet by Katy Muller & Helen Muller.
The book is £5.99 plus postage £1.50 UK, £5 worldwide.
A new 56 page updated version of the original publication, with new text and additional pictures. Buyer can request any signing of the book by the authors.
Copies of the book can be obtained by contacting Katy Muller: