Yes, Chris, I have also read somewhere that magnetite does exist in the human brain (and it is well-established that it exists within other organisms, too).

In regard to Fraser-Smith, I found this critique (specifically regarding Fraser-Smith's work) at UC Santa Cruz' "Science Notes" site - link below, interesting read:

"But critics of earthquake prediction, burned by exaggerated claims before, remain deeply skeptical. A region’s magnetic field is a morass of meaningless noise, they say, warped by everything from solar activity to electric trains to cell phones. From their perspective, deciphering a real earthquake signal amidst the junk is akin to picking out the hum of a single car zipping past on a crowded freeway. And researchers have failed to link these signals consistently to all earthquakes, making the claim of predictive ability “at best, a vast overstatement,” says Richard Allen, a seismologist at UC Berkeley"

Mike Williams

• "Science Notes"