Jet is a beautiful black mineraloid. It's not a true mineral because it is made from organic material - decaying wood under intense pressure. Jet is found in the Four Corners area near the Acoma PuebloIt has been prized for centuries, the Romans used it believing it to have healing properties. It was especially popular during the reign of Queen Victoria in England who began wearing it as "mourning jewelry."
Coal is created in much the same way as jet. However, this material is much less friable and can be cut, carved and polished to a bright luster. Its hardness is determined by whether it was formed by coming into contact with salt water (hard) or fresh water (soft). It is easy to cut yet it is hard to create fine details without breaking it, so it takes an experienced artist to achieve elaborate carvings. It is warm to the touch because of its ability to conduct thermal energy. It's harder to come by the real thing today and there are many imitations on the market. To know if your piece is made with the real thing, you can test it by rubbing it against un-glazed porcelain. True jet will leave a chocolate brown streak.
If you are looking to add a unique fetish to your collection, one made with this gorgeous black material is the way to go. Pieces made completely of jet are few and far between!