Jet: is a hard, coal-like variety of lignite. It’s color is velvety black or brownish black when passing into bituminous wood. It has a brilliant lustre and is resinous.This brittle material is formed when ancient waterlogged driftwood sinks to the ocean floor and becomes embedded in the mud.Through chemical action, pressure, and heat, the wood is transformed into a compact black fossilized material that is lightweight and fragile.Jet is well suited for carving and great amounts of jewelry were created.This demand for jet was so great, that the cliffside that were over the town of Whitby,England, were in dire straits of collapse. Mining for jet in Whitby was declared illegal due to the circumstances. Because of this shortage of jet, many substitutions were being used.
To test for jet, you can either carefully rub it across a sidewalk or unglazed pottery as this will produce a brownish, black streak if it is genuine jet. Another test is the hot pin test,once, heated red hot, introduce the hot tip of the pin into an inconspicuous area of the suspected piece, if it is jet, it not accept the pin easily and will emit very little odor or a slight smell of coal. Jet will also float or sink very slowly as it is very lightweight.When rubbed briskly onto silk or wool, true jet will develop static electricity and will pick up little bits of lint or paper.If burned, it will have a green flame and have a sweet bituminous smell. Jet is also warm to the touch.
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