Testing for Jet

As many of you may know, the most popular button of the 19th Century was the black glass button. It is said that they were made for the masses in response to Queen Victoria's use of black jet buttons as her mourning buttons — following the death of Prince Albert. Jet is made from fossilized evergreen wood and terribly hard to come by, so mourning button knockoffs were made from hard glass coal, horn, rubber and vulcanite.


The following tips for identifying have come from an article at https://www.thespruce.com/identifying-and-testing-jet.

1. Jet will be opaque black in appearance and will not have mold lines, so the first test is to inspect it visually.
2. It was also hand carved so no two pieces will be identical.
3. Most jet was highly polished, but pieces made for first mourning will be matte black.
4. Natural jet will be very light in weight in comparison to French jet, which is actually black glass.
5. It will also be room temperature rather than cold like glass. It's also interesting to note that jet will not scratch glass, but glass will indeed scratch jet.
6. Test by scraping an inconspicuous area on a rough surface like the back of a ceramic tile or the bottom of a piece of unglazed porcelain. If it leaves a brown mark, the piece is likely jet (although vulcanite can also leave a brown mark, so be sure to look for other jet attributes before making that call). 

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