Cheap lab to help ID my samples

[mario]

Hi guys,

I would like to know if anyone here knows a reliable,affordable lab that will help me ID the different mineral composition of my samples. I ground up some hotrocks that were given me a hard time with my PI metal detector, and would like to have the samples analyzed.

Thanks

Mario

[mikebg]

Hi guys,

I would like to know if anyone here knows a reliable,affordable lab that will help me ID the different mineral composition of my samples. I ground up some hotrocks that were given me a hard time with my PI metal detector, and would like to have the samples analyzed.

Thanks

Mario

Mario, some hot rocks are meteorites and some of them are very expensive. Each year on this date we observe an intense meteorite shower. Unfortunately the most expensive meteorites do not generate signal for metal detectors at air test. Search WEB for meteorites.

[mario]

Thanks Mike,

but the hotrocks im referring to are of a specific variety that I recurringly find at certain sites.

on certain instances I have found meteriotes. Although the ones I have found have been the more common nickel variety, I always look forward finding them.

I'm just curious about what specific minerals are triggering my detector.

[99thpercentile]

It sounds like you would like both quantitative and qualitative mineralogy on your samples linked to the relevant geophysical properties. The qualitative mineralogy would be a field geologic description of what the rocks are (i.e. sedimentary, igneous, or metamorphic and what type of rock such as limestone). The quantitative mineralogy would tell you the exact mineralogy of the sample. In my lab I use x-ray fluorescense (XRF) to determine the mass of each element in a sample, then I use x-ray diffraction (XRD) to determine the relative amounts of each mineral in a sample, the final step is to perform thermal analysis of the sample to see if there are any very low concentration constituents that were missed in the XRD analysis. I can do differential thermal analysis (DTA), thermal gravimetric analysis (TGA), or differential scanning calorimeter (DSC). The thermal analysis is really only necessary if the mass balance calculation from the XRF to the XRD show an imbalance. Then I would measure the electrical conductivity and magnetic susceptibility as a function of frequency, and the conductivity also as a function of water content.

I work in a government research lab so I'm not sure what a commercial lab charges for these services, but from what I listed above you should know what to ask for.

[homefire]

THE TESTS
How to determine if you have a genuine meteorite
1) Visual Inspection
If you've read the previous passages you now know much more about meteorites than the average person. Congratulations, and thank you for reading this far. Now, please carefully consider the following: Does your rock exhibit any of the characteristics discussed above? Does it feel heavier than it should? Does it have regmaglypts, or patina, or fusion crust? Compare your rock to the photographs of real meteorites, and meteor-wrongs.
2) The Magnet Test
Please remember, a meteorite will stick easily to a good magnet. If your rock does not adhere to a powerful magnet you almost certainly do not have a meteorite. There are many Earth rocks that also stick to magnets, so if your specimen adheres to a magnet it is not automatically a meteorite, but it's a step in the right direction.
3) The Streak Test
Iron oxides like hematite and magnetite are the Earth rocks most frequently mistaken for meteorites. They are moderately heavy (not nearly as heavy as iron meteorites) and appear metallic in composition. Some specimens will stick to a magnet. If you think you have an iron meteorite, here's an easy test you can perform at home: Take your rock sample and scrape it against the coarse (unglazed) face of a white bathroom tile, just like you were drawing on a blackboard with a piece of chalk. If your rock leaves a reddish or rust-colored streak on the tile it is likely hematite. If it leaves a dark gray streak it is likely magnetite. This test only works on iron meteorites (not stones). A genuine iron meteorite will typically leave NO STREAK, or possibly a very faint grayish mark. Please note that the streak test only works on iron meteorites.
4) The Nickel Test
Most meteorites contain a significant percentage of nickel and iron. Naturally occurring Earth rocks do not, so if your specimen tests positive for nickel it may be a meteorite. Kits that test for nickel can be purchased via the internet, or you can take your rock to a lab that assays (tests) for various mineral components.