Some sources believe jet is a lignite coal, but others disagree asserting jet to be a product of the decomposition of a particular species of tree, the Araucaria.
While used since ancient times for ornaments and jewelry, it reached its height of popularity during the Victorian era.
Jet has a very low density, so it is light and suitable for large pieces of jewelry.
But it is also quite soft compared to most gemstones, with a hardness of only 2.5 to 4.0 on the Mohs scale.
Jet has also been called "Black Amber," as it may induce an electric charge similar to Amber when rubbed.
HISTORY
Jet is one of the oldest materials used in making jewelry;
jet ornaments exist since the Bronze age and during the Roman occupation of Britain jet was largely used.
The Romans called it "gagat", which is probably the source of the word 'jet'.
The Greeks also valued the mineral, and used it also as a healing essence: its powder was used to prevent toothache, and when burned as incense it was supposed to drive away devils.
FEATURES AND TESTS
True jet is lightweight. Finished pieces characteristically have sharp precise cuts.If subjected to a hot point (though not recommended) it will give off an oily or coal like odor.
When rubbed with wool it will develop an electrical charge, similar to amber.
The most definitive test is its streak. When rubbed against an abrasive surface, it will leave a brown streak. This is also a somewhat destructive test, which must be used with great caution.
There are no known enhancements of jet.
IMITATIONS
Jet is one of the very few material featuring natural solid black colour.
‘French Jet’ is an imitation commonly available in the market, it is actually black glass;
gutta-percha and vulcanite are two man-made materials; bog oak is also an imitation of jet.
The most common surrogate of jet is onyx, a variety of chalcedony, which is dyed to produce a uniform black.
METAPHYSIC AND HEALING PROPERTIES
Jet is commonly used as a stone of protection, yet it also carries some wonderful healing properties, including pain relief for headaches/migraines and enhanced healing of traumatic injuries.
Also known as a stone of good luck, Jet makes a great gift for the person starting a new job or beginning a new business pursuit.
Jet can bring clarity to a confusing situation by bringing unique insights from variant perspectives.
Those who are struggling through multiple trials and tribulations will appreciate Jet's supportive energies.
Jet can also be helpful for those experiencing an overabundance of negative energies or emotions, and has traditionally been used as a stone to alleviate grief.