![]() Most of the instruments are designed or programed to do analysis of metals, not rocks, so, for example, there are no data for Si (silicon). Most of the results that I have been sent from XRF guns, however, have not been useful to me for determining if the rock is a meteorite. Hand-held XRF Analyzers I know a few meteorite finders and collectors who use hand-held XRF “guns” to recognize meteorites. Unfortunately, I do not know a lab that does this cheaply. Iron Meteorites If you have a chunk of metal that you think might be an iron meteorite, you need to have it analyzed (at a minimum) for iron (Fe), nickel (Ni), chromium (Cr), and manganese (Mn). Check your own data with “ Chemical Composition of Meteorites“ Half of these were from northern Africa or the Middle East and a couple, I believe, were stones that someone had bought or inherited. Only 6 of the “rocks” have meteorites, 4 ordinary chondrites, 1 pallasite (not listed above), and 1 iron meteorite. ![]() July, 2021: I have received results of analyses of 615 samples from Actlabs and more than 100 samples from other labs. Let me do the interpretation of the data. They do not classify meteorites and they do not issue “certificates of authenticity.” They provide a report of the composition. Please, do not bother Actlabs with questions like “Is this a meteorite?” They just analyze. Rock-type identification requires other kinds of tests. If I conclude that the composition of your rock is not consistent with any kind of meteorite, then I may not be able to tell you just what kind of rock it really is. Send me a copy of the report (the XLS file) that Actlabs sends you and I will tell you whether the rock composition is consistent with that of a meteorite. LOI is sometimes useful, but never critical, for determining whether or not a rock is a meteorite. However, they can do the analysis on as little as 1 gram if you request “no LOI” (loss on ignition, i.e., % weight loss when the sample is heated to a high temperature). Actlabs requests a 5-gram sample (a US nickel weighs 5 grams). Before contacting them, however, contact me first for some advice. I have no financial interest in Actlabs, I just know they do a good job. Ask for analysis code Meteorite(ICP/ICPMS). For many years I have recommended Actlabs. ![]() Data for As, Cu, Zn, and the rare-earth elements would be useful, too. With data for those elements, I can say “yes” or “no” with considerable confidence 99% of the time. At a minimum I need data for Si, Al, Fe, Mn, Mg, Ca, Na, K, Cr, and preferably Ni and Co to determine if the rock is a meteorite. For that, you need to send a sample to a commercial rock-testing laboratory. As a geochemist, I suggest whole-rock analysis of chemical composition. Stony Meteorites There are several different ways to test if a rock is a meteorite. I do not analyze or “test” rocks to determine whether or not they are meteorites. I am retired and no longer have a laboratory.
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