[meteorite-list] Nickel found in hematite and magnetite?
From: cdtucson at cox.net <cdtucson_at_meteoritecentral.com>
Date: Sun, 13 Mar 2011 22:26:32 -0400 Message-ID: <20110313222632.IINHT.42707.imail_at_fed1rmwml38> Dan. thank you for your info but, There is no way we are talking about the same XRF gun. Blain's gun does in fact give data in percentages as if the rock was assayed. I saw it with my own eyes. We did several test samples of real and well known meteorites. During this test we read the digital results directly from the gun itself and then compared the knows with the percentage results from the gun. We also did irons and the nickel showed in percentages. One guy brought in a mill ball that had NO nickel but known irons showed exactly the known nickel percentages. ie 6% or 12% etc... In our tests the only real limitation the gun had was the measurement of the lighter elements but only that it did not define and or separate them. It gave them as a bulk percentage such as ( light elements) LE= 42%-ish. For that reason It also failed to give Cr which is a real bummer because Cr is a very telling thing in planetary material. As the moon has way more than earth for example. May be in the order of 100 x . Yes, You and Blain do need to talk because apparently his $40,000. gun does do a lot more than the one you have. To be fair. Blains gun has different settings. We used the same setting ( miner ) on the real known meteorites as we used on all of my samples to give us a basis for comparison. Yes, adjustments did have to be made according to Randy Korotev but, once you do the conversion from element to oxide the numbers match up pretty well with the known percentages in the known meteorites that we tested. I should note that Blain has no intention of classifying meteorites. This is simply a weed to rule strange rocks out. Not to prove they are meteorites. We did end up with a few really good prospects though and this without wasting any scientists valuable time. Here is a list of the samples we tested for use in comparisons.; NWA 4857 MARS NWA 6355 LUNAR NWA 4734 LUNAR NWA 480 MARS Again, We zapped the above meteorites with Blain's gun and then compared the percentages with the known published percentages and they were a very close match once we converted the elements to oxides . Which is how they are published in the bulletin. So, I hope you and Blain do get together. It is hard to believe these match by coincidence alone? For those of you who may not know Blain. Blain Reed Meteorites is a major meteorite dealer. Thanks, Carl -- Carl or Debbie Esparza Meteoritemax ---- Dan Wray <daniel_wray at comcast.net> wrote: > Carl, > > You are right, the nickel chemical test has lots of problems with false > positives, not to mention a short shelf life after mixing. On the subject > of XRF guns, they will tell you that nickel is present but not the > percentage. The software claims that, but it is bogus. I am an operator > for our XRF gun at the Geology Museum at the Colorado School of Mines. We > have done extensive testing of this machine and found that it has severe > limitations. Here are the results of a study done at the museum: > 1. XRF can only identify elements and can predict almost nothing about > quantities. > 2. Most of the time it can identify the presence or absence of elements, but > not all of the time. The software will identify elements that aren't there. > You have to read the spectra to determine if the alpha and beta lines are > indeed there. Large amounts of lead or iron, (i.e.. meteorites), will block > other readings. > 3. Avoid quantities, one can't even say that there appears that there is 3x > as much A as B. The only way this works is with man made alloys and pure > samples that the machine can be calibrated to. > > The only good part is that I can test for nickel with a high degree of > accuracy in about 30 seconds and tell the meteorwrong bringer that I used a > scientific test to prove, what I probably already knew, that what he has is > definitely not a meteorite. It has also allowed us to correct specimens in > the collection that are mis- identified. > > Blain, you need to come over to the museum, we have much to share. > > Dan Wray > > ----- Original Message ----- > From: <cdtucson at cox.net> > To: "Paul G. Spears" <pgspears at cox.net>; "meteoritelist" > <meteorite-list at meteoritecentral.com> > Sent: Sunday, March 13, 2011 9:37 AM > Subject: Re: [meteorite-list] Nickel found in hematite and magnetite? > > > > Paul, > > I find tons of what you are describing. > > Color tests work on almost any amount of nickel and also give false > > positives based on knowing exactly what shade of red to look for. I don't > > know which red is the correct red. > > I have an AXE that tests bright red with a red color nickel test but in > > actually only has only a trace amount of nickel and scientists believe it > > needs more than just a trace. I may never understand why that is. I have > > been told that " nature has no way of separating the metals " but if that > > is true then why is there always a different percentage of nickel and why > > can it be as high as 60-ish percent and as low as just a few percent? > > That said, If it is a highly oxidized iron meteorite it would have a > > relatively high percentage of nickel as opposed to just a trace > > percentage. > > Blain's XRF gun gives complete analysis in percentages and would tell you > > if it has several percent nickel. if it does then the core of the rock may > > still be shiny iron. You could cut it in half and look inside. > > Blain offers this service and it is quick and inexpensive. Well worth the > > cost and the only way to be certain. > > Carl > > -- > > Carl or Debbie Esparza > > Meteoritemax > > > > > > ---- "Paul G. Spears" <pgspears at cox.net> wrote: > >> In a specimen that may be a hematite, a strong presence of nickel was > >> found. > >> Is that possible? While the specimen is very attractive to magnets, > >> tests > >> positive for nickel, and looks and weighs like iron, it has many pock > >> marks > >> and some white inclusions that may be quartz. Anyone come across similar > >> specimens? > >> > >> > >> ______________________________________________ > >> Visit the Archives at > >> http://www.meteoritecentral.com/mailing-list-archives.html > >> Meteorite-list mailing list > >> Meteorite-list at meteoritecentral.com > >> http://six.pairlist.net/mailman/listinfo/meteorite-list > > ______________________________________________ > > Visit the Archives at > > http://www.meteoritecentral.com/mailing-list-archives.html > > Meteorite-list mailing list > > Meteorite-list at meteoritecentral.com > > http://six.pairlist.net/mailman/listinfo/meteorite-list > > >Received on Sun 13 Mar 2011 10:26:32 PM PDT |
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