Professor Steve Jones has done some incredible work with WTC dust, analyzing the magnetic particles in each of his samples. I've duplicated some of his early findings by separating the magnetic fraction in my WTC dust sample, in the way he described in his paper at the following link. Here Dr. Jones explains some of the implications of these findings, and considers options for the source of what he learned to be iron-rich spheres.


http://www.journalof911studies.com/volume/...11SciMethod.pdf

Similar spheres were also found by other investigators, including the R.J Lee company and the USGS. But although the EPA considered "iron spheres" to be a potential signature component of the WTC dust, it rejected using them as an indicator, along with asbestos and PAHs, for unidentified reasons.

http://www.epa.gov/wtc/panel/pdfs/SubGroup...ents_110305.pdf


Such spheres would form in the molten state due to surface tension of the metal as it fell or was sprayed from a high temperature source. The presence of iron spheres in the dust indicates temperatures of at least 1500 °C, much higher than anything NIST suggests even in .......
http://www.opednews.com/articles/life_a_ke...microsphere.htm