meteorite or iron slag?

Question

This very heavy piece was found by my son as we went off roading in Central Cal. it looked like no other rocks around in shape and color. It is black on the outside and pale grey brown on the inner chipped off surface.When I filed one area on an already chipped off end, it appears shinny gray silver. It has only a slight magnetic attraction. I have looked up both iron ore and meteorites and it resembles both. stumped? added tid bit I compared with hematite and it has nowhere near the magnetic attraction...I guess that I need to test for nickel content next? anyone?

Answer 1

Usually where there is slag you'll find other pieces of slag. See if there are other similar pieces in the area, that can be a giveway. Iron-nickel meteorites are usually strongly attracted to magnetic fields, and will also conduct electricity, so you can testing that as well. Read this page for more info: http://www.minerals.net/mineral/iron-nickel.aspx

Answer 2

Thank You Hershel for getting back on this. I did read the page from your link. This specimen appears to only have a mild attraction to a magnet in certain areas on it's surface. It has a few areas that have an ever so light appearance of rust....most of the surface is black. I filed a small portion on what I would call the top, an area that looked to be chipped off to reveal a graphite/ nickle semi shiny surface. Elsewhere on the surface there are very small exposed areas that have specks of very shiny silver dots. I did not see any other pieces in the area where I found it that resembled it...it just stuck out as being different, that's why we picked it up. It is beyond belief heavy and yet surprisingly soft when it was filed. The filings did pick up with a magnet. How does one test for electric conductivity? Is there a place I can send a sample to have it tested?

Answer 3

True iron-nickel meteorites will have a strong attraction, so that would likely rule it out. The rust definitely sounds on target, but another strange thing is that you describe it as being very light, when in fact iron-nickel meteorites will be heavy.

To test conductivity, use an ohmmeter. Take a look at this link: http://www.ehow.com/how_2046943_test-conductivity-metal.html If you don' have access to an ohmmeter, you can use a battery operated flashlight and wires and try running one of the wires through the stone to see if the electricity passes through.

Answer 4

It is not light..it is very very heavy...magnets stick to it, some areas more than others..

Answer 5

I believe I have solved this...think it is ferromanganese..a form of slag. After more research found this image that looks much like my piece down to the dark surface that looks like a crust...very often mistaken for meteorites.The site that discussed this says not to grind or slice it as it can contain lead and arsenic....Oh great