I still don’t believe it caused cancer in all these people. It was a band wagon.
Asbestos and talc naturally occur together in metamorphic rocks, with the gradation between the two depending mainly on the heat & pressure of formation. It’s not like J&J spiked their product with asbestos.
Visual examination with a polarizing optical microscope is the only way, I believe, to differentiate talc and asbestos and perhaps other minerals in the same series. Chemically they are identical, only the “habit” ie. crystal formation differentiates these minerals. Getting a little asbestos in talc while mining is understandable.
Supposedly asbestos causes cancer because it forms in long, fragile crystal spikes sometimes visible, but also narrow enough, smaller than a cell, to penetrate individual chromosomes or telomeres and cause mutation in lung cells.
Last I heard no one had proven the talc caused cancer. They convinced a jury it did…but that’s a much easier thing.