Some years ago I found a strange rock on the river bank near my home. It has only just dawned on me that it might be a meteorite. It is about 17cm at the widest diagonal and weighs 900g. When my daughter passed her metal detector over it, it gave a signal. It feels very heavy for its size and has a metallic ring to it. There also appears to be a thin, more shiny, layer on the surface that has been worn away at the extremities, probably from being in the river.
It was its strange shape that first atracted me to pick it up. Looks a bit like a seal! Pictures below.
Could anyone tell me if this could be a meteorite please?
That is, indeed, a strange shape...
Have a go at the tests in these pages, then report back please:
- http://epswww.unm.edu/iom/ident/index.html (also a useful table of densities)
Well, I have had a go at calculating the density and have come up with something between 3.1 and 3.5. I can't find a magnet to test it although it does contain metal according to the metal detector. It has a smooth surface with no sign of any other kind of rock contaminating it. The crust could have been smoothed down by the river. Is a little pitted here and there. Still not sure. Could it be basalt? I will try to get my hands on a magnet tomorrow.
The ability to 'ring' suggests it has a significantly uniform interior (though sonorousness can be enhanced by external shape, too; as in a bell). That leads me to believe it has a fine-grained structure (also obvious from the smooth surface). Fine-grained high-grade metal ore would be a possibility but for your specimen not being dense enough; eg. chromite has a density of about 4.8g/cc.
There are numerous reports of ringing rocks, in less metalliferous rock types (long article here), which could include basalt. But I am not particularly drawn to the idea of basalt, based on the appearance of your specimen, and its being a bit too dense. There are related denser rocks (eg. peridotite, up to 3.4g/cc), but they tend to be coarser grained.
Let us know the reaction with your magnet;
and with a non-megnetized piece of steel, such as a kitchen knife.
Streak test result?...
I'm guessing you would not want to break it open...?
(If it was mine, I think I would rather not.)
Can you tell me where it was found (which bit of which river).
I would then be able to check the geology of the area, and I might be able to find some relevant industrial history, too.
(Grid ref., Google map link, description, etc...)