METEORITE OR METEORWRONG?

slag

Many of the meteorwrongs sent to us are pieces of slag. Slag usually refers to a glassy by-product of smelting ore to retrieve the metal. I use the term here to also include any man-made, rock-like by-product of heating things to high temperature. Thus, clinkers are a form of slag. Slags catch people attention because of their morphology. Many slags contain metal and will attract a magnet from inefficient separation of metal from the ore. Two other common characteristics of most slags are are glassy (vitreous) surfaces and the presence of vesicles (gas bubbles). Slags are sometimes used in road construction and as landscaping gravel, so they're more common that one might think.

I have not personally examined all the examples pictured below, but I suspect they are all slags. If they're not, then they are volcanic rocks. None of them are meteorites.

Glassy and vesicular

Flow features on a flat surface are sometimes seen on slags.

A magnet sticks to this one.

These for rocks were found in a freshly mulched flower bed. The one on the lower left may be a "just a rock." The other three contains metal, vesicles, and glass, so they're slags.


Glassy and vesicular