This motorcycle fork oil was not the best in terms of quality. I am not a specialist but my guess is that it has become unstable for some reason and has braken apart in the bottle.
There have been no introduced contaminants, it was just standing in the original clean bottle.

I have been in contact with Penrite, and initially they said they will replace the bottle, but then stopped responding to my emails. Well, would just have to buy some other oil and steer away from the brand in general.