Pre-mastered MDs are pressed and the format is physically similar to CDs. I would be interesting to put this disc under an optical microscope, I assume it would

Pre-mastered MDs are pressed and the format is physically similar to CDs. I would be interesting to put this disc under an optical microscope, I assume it would look similar to a regular pre-mastered disc but perhaps it's actually a recordable MD (which look very different) or some kind of R&D experiment. I took a bunch of optical images of MDs and other formats here for reference: https://everydaything.substack.com/p/a-pre-mastered-minidisc https://everydaything.substack.com/p/a-pre-mastered-minidisc This can be done non-destructively with an inexpensive epi-illuminated microscope.