as a rockhound, I always try to find new stuff. from agates tot petrified wood and so on...
last summer I stumbled on a good portion of JET ( gemstone ) on the beaches of the river rhine in Nordrhein-Westfalen ( GERMANY )
it is amazing material... and it has amazing properties.
with Jet everyone thinks of the color black, because of the adjective 'jet black'. JET ( GIT in Dutch ) is indeed pitch black, or very deep dark brown. Jet may also contain glittering flecks of pyrite.
JET is charred fossil wood about 150-200 million years old. Because of its beauty, Jet is still counted among the gems.
The wood structure of Jet can still be seen clearly under a good microscope. It is not completely petrified yet, but it is on its way to becoming coal, as a result of further carbonization.
Git is sometimes referred to as lignite. Wrongly. Lignite is approximately 2-5 million years old, so it is much younger than the real Jet. It is fossil wood that has been reduced to brown coal. Lignite is sometimes processed into jewelry and offered on the market as Jet.
The official name is Jet.
The other old name that is no longer in use: black amber.
Due to its low specific weight, Jet is easily carried with the waves and deposited on the shore of the coast of the Netherlands or at the river beaches. Unfortunately, it is difficult to recognize, especially because environmental pollution causes many dark oil residues to end up on our beaches.
here is the making of the GEM you see in the first picture...