Honestly I doubt anyone would just have that info on hand. Would be more likely to find an answer with google. I have never bought only glass for a mirror in 20 years of driving n working on vehicles.
Problem with mirror glass solved GM Part # 88986364 it was really bad with bad blotches of brown discoloration which I guess was the photo-chromatic fluid between the two plates of glass that provides auto-dimming.
Thank You...