Scratch test

Meteorites do not easily scratch glass

Meteorites do not contain any substantial amount of quartz, whereas quartz is common in many terrestrial rocks. Quartz is harder than any of the common minerals in meteorites. Quartz is so hard that it will easily make a deep scratch in glass. Even if you press hard, a meteorite will at best only make a weak scratch mark. (Use a sharp edge of the rock.)

The top scratch was made with a quartz crystal. The next mark was made with a piece of chert, which is another form of quartz. The two scratches at the bottom were made with ordinary chondrite. Ordinary chondrite 1 left some rusty material along the weak scratch mark.

Bottom Line:

If you have a rock that bites into glass and makes a scratch mark like the two at the top of the photo above, then it contains quartz and it is not a meteorite.

If your rock does not make a scratch, then the rock is still probably not a meteorite because many terrestrial rocks do not contain quartz.

back to “Some Meteorite Realities”