Authenticating Jet
Although now much less popular than in the past, authentic jet jewels are valued by collectors.
Unlike black glass, which is cool to the touch, jet is not cool, due to its lesser thermal conductivity.
Anthracite (hard coal) and Ebonite (hardened rubber) are superficially similar to fine jet, and have been used to imitate it. These imitations are not always easy to distinguish from real jet. When rubbed against unglazed porcelain, true jet will leave a chocolate brown streak.
The microstructure of jet, which strongly resembles the original wood, can be seen under 120x or greater magnification.
Read more about this topic: Jet (lignite)
Famous quotes containing the word jet:
“Gimme the Plaza, the jet and $150 million, too.”
—Headline, New York Post (Feb. 13, 1990)