I believe that hematite is mildly magnetic. And I recall hearing that with the magnetic hematite "fad" that people/Companies were using strong magnets to make the synthetic hematite magnetic- though I always doubted this claim. Found two sources that could be helpful.

Artificial Magnetic hematite is evidently NOT real hematite- but may be in fact a barium-strontium ferrite magnet (AKA ferrite) that has the magnetoplumbite structure instead. MinDat.org: https://www.mindat.org/min-35948.html

Is magnetizing hematite possible? Dept.of Physics, Univ. of Illinois: https://van.physics.illinois.edu/qa/listing.php?id=357&t=hematite-magnets

Though hematite is a first choice for the appearance of shiny black material in your pendant from Mexico, Obsidian, a volcanic glass, is also black and shiny, and can be magnetic as well, depending on source location. North American Archaeologist Journal: https://journals.sagepub.com/doi/abs/10.2190/QG75-MVKT-HE33-5VAQ?journalCode=naaa

Hope this helps,
Anne