Most other gemstones do not leave a streak on porcelain except for ebonite and vulcanite. Therefore, make sure that the piece of jet ticks all the other boxes before making your decision. TEST 4: Take a good look at the gemstone in question and check for signs of moulding or fading due to sunlight. If the colour has changed to more of a khaki shade then the gemstone is definitely not genuine. TEST 5: A more invasive, risky test is to take a red hot needle and place it on an area of the gemstone that is not so noticeable.
Upon placement it will smell of burning coal however, if you do decide to take this route it is important that you do not damage the piece you are trying to identify.
As the cliffs along the North Yorkshire coastline gradually erode into the sea thin seams of Jet are exposed and often end up being washed into the sea. After a storm small pieces are washed up onto the beaches around the town of Whitby. The video below shows how to test the quality of any Jet found.
If you chalk the piece of Jet on sandstone or emery paper it should leave a brown mark. The best quality Jet will leave a light brown ginger mark. This is hard Jet and the only type that should be used to make Jewellery. If the Jet leaves a dark brown mark it means it is poorer quality soft Jet. Although this may still take a polish it may break up or crack over time. Whitby Jet was formed from the fossilised wood of the Araucaria araucana Monkey Puzzle and other similar trees that grew in the Jurassic period around - million years ago.
After the trees had died and fallen some were washed down into the shallow water of the Yorkshire basin where they became waterlogged and sank to the seabed.
As the trees washed down the rivers they would often be stripped of their branches or broken up. In the black mud anaerobic decomposition started to occur.
Over millions of years the pieces of now pulpy driftwood were compressed as layers of organic rich sediment built up over time, creating extreme pressure and chemical change. The Jet would absorb the oils from decaying organic debris and marine plantlife such as plankton and algae. Hard and Soft Jet. Hard Whiby Jet is the only Jet that is suitable for use in Jewellery manufacture and was formed in salt water. Soft Whitby Jet was formed in a fresh water environment and is not suitable for jewellery.
Soft jet is liable to crack or break after a period of time or when exposed to the sun. Whitby Jet has a hardness of 2. It also has a low specific gravity meaning larger brooches and beads can be worn in comfort such as was seen in the Victorian era when large items were at the height of fashion.
Early on, jet was used by the ancient Romans to craft elaborate jewelry and by Native Americans for the ornamentation of weapons. In the 19th century, its use flourished in Europe as one of the few substances appropriate for mourning jewelry.
It was worn outside of mourning too. Its use declined after , replaced by cheaper options like black onyx chalcedony , black tourmaline, black glass "French jet" , and vulcanite. Around the turn of the 20th century, dwindling supplies of quality material, preferences for more delicate pieces jet jewelry tends to look massive , and less rigid mourning-dress practices contributed to a loss of interest in the jet material.
The pliable nature of jet allows it to be carved, faceted, and polished to a soft warm sheen. Jet jewelry intended for first mourning the months just after a loved one's passing was polished to a matte black finish. However, most pieces found today have a polished, glossier appearance. Jet was used to craft beads and other necklace components which were then strung or linked together with wire. Brooches that display intricate carvings were also constructed with this stone, as were earrings, pendants, and finely crafted jewelry sets.
Today, jet jewelry is coveted by Victorian period collectors and can be found in antique shops, online, and sometimes at flea markets. Jet can be safely washed in a mild detergent and warm water.
It is recommended that moistened cotton wool swabs be used to gently remove any surface dirt. Always keep Jet separate from other jewellery since it is relatively soft and can easily be scratched. It is suggested that each piece should be wrapped in tissue paper to prevent rubbing against other items. What is Jet? What sort of items were made from Jet? Where can I see items made from Jet? Where is Jet found?
How can I tell real Jet? How were Jet items made? Where can I find further information on Jet? Where can I buy Jet? How should I care for my Jet? Photograph of thin section of Jet.
Woody tissue which has escaped compression with granules of quartz Photograph of thin section of Jet. Woody tissue which has been greatly compressed with particles of quartz. Like this: Like Loading Follow Following.
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