It's...

....a rock drill bit. This particular bit came from the Sterling Hill Mining Musesum in Ogdensburg, New Jersey.

Zinc was mined in northwest New Jersey until recently. It is also home to a highly concentrated number of fluorescent minerals. I highly recommend a visit if you're in the region. Many of the tour guides are gentlemen previously employed as miners at the mine - they provide quite a perspective as you tour the actual mine. In addition, there's a wonderful gift shop filled with various mining artifacts - I love my dynamite box! Great for school groups as well as families.

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What Is It? is a feature you can add to your classroom. Once a month, or thereabouts, put out something new and ask students to try to identify it. If they figure it out correctly, give them extra credit, a prize, a high five or bragging rights!