Liberty: You should simply read the Bentham paper again and more carefully.
For your convenience, here are quotes from the paper, as regards those platelets in chips (a) to (d):
"These bright particles (
iron oxide, I.K.) are seen intermixed with plate-like particles that have intermediate BSE intensity and are approximately 40 nm thick and up to about 1 micron across... The plate-like particles with intermediate BSE intensity appear to be associated with the regions of high Al and Si. The O map (d) also indicates oxygen present, to a lesser degree, in the location of the Al and Si. However, it is inconclusive from these data whether the O is associated with Si or Al or both."
As you can see, there is no mention about elemental Al even in the Bentham paper itself. All it is written there
(concerning chips a to d, since MEK chip was clearly different material) is basically consistent with some aluminosilicate and, moreover, those platelets look exactly like kaolinite in such magnification.
Btw, yesterday, in my private message to Chrismohr, I again suggested the FTIR microscopy as the most suitable/cheapest method for us and I recommended services of companies like this one:
This company is specialized on the analysis of paints.
Some citations from the
"FTIR spectroscopy combined with microscopy allows analysis of small particles down to 10 um. The ability to analyze these subvisual size samples allows materials such as paint media to be analyzed without removing a noticeable amount of material. FTIR is particularly well suited for analysis of materials that have distinctive functional groups including esters, carboxylic acids, amides, proteins, alcohols, and carbohydrates. This means FTIR is a very capable technique for medium identification, polymer analysis, and coatings characterizations."
"FTIR Microscopy Applications
·Fast accurate analysis of paint media
·Identification of dyes and pigments
·Identification of fibers
·Characterization of coatings and polymeric materials"
Quite clearly, this is a method of first choice for us, since it can characterize/analyse individual paint (or nanot...e

) chips.
(Laclede paint chips could be distinguished from Tnemec paint chips using characteristic infrared bands of epoxy and alkyd/linseed based resins, which were the binders used in Laclede and Tnemec primers.)