Update July 04, 2015: The links to References - were broken, I updated them to new URL's. This also changes the timestamps in the video. I also re-formated the section headers and renamed the section "Footnotes" -> "References". Additional remark: I incorrectly wrote that chips a-d were the same as the four chips tested in the DSC and presented as Fig. 19 in Harrit et al. Today I know this is wrong; I keep this article as it was, regardless.
Update July 15, 2018: The links to References  and  were again broken, I updated them to new URL's. The timestamps in the video remain the same. I also moved the link to Sunstealer's post at JREF to the References as 
This post elaborates on a great find made by poster "Sunstealer" in the former JREF Forum (now ISF - International Skeptics Forum) 
In their paper "Active Thermitic Material Discovered in Dust from the 9/11 World Trade Center Catastrophe" of April 2009, the authors sought to identify the chemical nature of tiny "red-grey chips". In November 2009, one of the authors, Steven E. Jones, presented new data in Sydney, Australia. This new data proves that the authors had looked at two different materials, and that one of them is primer paint from WTC steel. At the same time, it invalidates two of the main conclusions of the paper, namely Conclusion 3 ("Elemental aluminum became sufficiently concentrated to be clearly identified in the pre-ignition material") and Conclusion 6 ("From the presence of elemental aluminum and iron oxide in the red material, we conclude that it contains the ingredients of thermite."), as well as the main conclusion ("we conclude that the red layer of the red/gray chips we have discovered in the WTC dust is active, unreacted thermitic material...")
Analysis of chips in Harrit e-al., April 2009
In their paper, the authors of  looked specifically at five reddish dust chips:
- The first four are labeled (a)-(d) on page 10 and first subjected to analysis by SEM imaging (Fig. 2), BSE imaging (Fig. 5, 8) and XEDS spectroscopy (Fig. 7, red layer), and were later burned in a Differential Scanning Calorimeter (DSC), yielding energy releases of 1.5, 3, 6 and 7.5 kJ/g. I will refer to these as "samples a-d"
- The fifth is described in section 2, pages 15-19, and was first soaked in MEK for hours, and then subjected to photomicrographing (Fig. 13), XEDS spectography (Fig. 14) and BSE imaging (Fig. 15). This sample was not tested in a DSC. I will refer to this chip as "MEK sample"
While it bears noticing that the photos of samples a-d versus MEK sample show only superficial similarity (the MEK sample is about 4 times thicker, with no apparent grey layer, and looks less uniform; they all just happen to be reddish), a very stark difference shows in the XEDS spectra:
The differences are striking: While samples a-d are very similar, with noticable peaks of C, O, Al, Si and Fe (only sample c appears contaminated with traces of Na, S, Ca and K), the MEK sample is dominated by O and Ca, has a higher peak for S than for Al, and also features Zn and Cr, two elements seen in none of the four other samples. Notice that there is a small peak at about 1.2keV, that isn't labelled, and two others at about 3.35keV and 5.9keV.
The conclusion is obvious and inescapable: samples a-d are the same material, the MEK sample is a different material. It follows that any results that the authors find for the MEK sample cannot be applied to samples a-d. The authors hand-wave these results by speculating on surface contamination (p. 17). But this is not confirmed by any tests. We must assume, for the moment, that the MEK sample is of a different material than samples a-d, and that the finding of elemental Al in it (dubious as this is in itself) cannot be extrapolated to samples a-d.
New data from November 2009 presentation
Is it possible to find a better explanation for the presence of the other elements, and identify the material of the MEK sample? Yes, it is, and the data comes from co-author Steven E. Jones, who delivered a presentation about 9/11 on November 14, 2009, in Sydney, Australia. This presentation is available on Youtube. Jones presents data obtained from primer paint that was scratched off of a piece of structural steel from the World Trade Center (possibly 55th floor of the South Tower). Here is a screenshot from 35min:36sec of that Youtube presentation:
Fig. C: Screenshot from Jones-presentation in Sydney. On the left: samples c and d from ; on the right: XEDS spectrum of WTC steel primer paint
Jones notices, correctly, that these spectra are of different materials. However, he fails to notice that the spectrum on the right is very similar to the spectrum in Fig. 14 of : The MEK sample! A comparison of these two spectra shows, from left to right:
- 0.28keV: both have a high peak for C
- 0.54keV: both have a high peak for O
- 0.71keV: both have a medium peak for Fe
- 1.02keV: both have a small to medium peak for Zn
- 1.25keV: both have a small peak for Mg
- 1.49keV: both have a medium peak for Al
- 1.74keV: both have a medium to high peak for Si
- 2.31keV: both have a small to medium peak for S
- 3.31keV: both have a small peak for K
- 3.69keV: both have a high peak; for sample a-d it is labelled "Ca", for the primer paint it is labled "C". I propose that one of the two lables is in error. Should be Ca in either place
- 4.01keV: both have a small to medium peak for Ca
- 5.41keV: both have a small peak for Cr
- 5.95keV: both have a small peak for Cr
- 6.40keV: both have a high peak for Fe
- 7.06keV: both have a small peak for Fe
- 8.64keV: both have a small peak for Zn
Discussion and Conclusions
These similarities are so striking, that we may conclude: The MEK sample was primer paint from WTC, while samples a-d were not It bears repeating that Harrit e.al.  provide no evidence for elemental Al in samples a-d, as they separated Al in a different material, namely primer paint, without noticing it.
The conclusions of Harrit e.al. (red layer being unreacted thermitic material) hinge on the alleged observation that the red material found in the dust
a) is always the same
b) contains Fe2O3
c) contains elemental Al
d) burns vigorously
Jones' new data shows a) to be incorrect. c) is shown for the MEK sample only, d) is shown for samples a-d only.
We have to reject the main conclusions of Harrit e.al.: They have not shown that the red-grey chips contain unreacted thermite. In fact, they have failed to identify the composition and nature of samples a-d. However, we now know that the MEK sample is simply primer paint.
Jones goes on in his talk to commit a major blunder: At 37:30 in the video  he presents this slide, which claims that the MEK chip contains no Zinc. This is directly refuted by Harrit e.al., Figure 14, which shows two XEDS peaks for Zinc, at 1.02 and 8.64keV!
 Niels H. Harrit, Jeffrey Farrer, Steven E. Jones, Kevin R. Ryan, Frank M. Legge, Daniel Farnsworth, Gregg Roberts, James R. Gourley and Bradley R. Larsen: "Active Thermitic Material Discovered in Dust from the 9/11 World Trade Center Catastrophe"; The Open Chemical Physics Journal, 2009, 2, pp. 7-31
 Steven E. Jones: "Steven Jones 2009 "Science and Society""; Presentation in Sydney, Australia, on November 14, 2009
 ibid, starting at 35m35s
 Energy values for all elements can be checked at http://csrri.iit.edu/periodic-table.html. There is the K-alpha value of 3.69 for Ca, but none in that vicinity for C.
 "Sunstealer": International Skeptics Forum (formerly: JREF Forum) - Thread "The sad case of Niels Harrit" - Post #536.