I Reflectivity of Pure Metals in Vacuum

[jms4]

All data I see online about reflectivity of metals is about aluminum in the atmosphere meaning oxidized aluminum, but pure aluminum in vacuum in case of the James Webb telescope would also be extremely reflective but building it on Earth means it's going to get oxidized, similarly there are a lot of pure metals out there which would be very reflective in vacuum such as calcium or magnesium or titanium if they wouldn't oxidize in the atmosphere. Is there any data about most reflective materials pure materials in vacuum?

 

[russ_watters]

Do you have an example source you can provide? I feel like there may be a disconnect between the question and the answers you are finding, as a quality source should be giving you exactly what it tells you it is giving you. If it says reflectivity of Al it should be reflectivity of Al, not Al2O3. There are work-arounds to the problem of working in the atmosphere, though they may be too cumbersome to bother with for anything but a scientific investigation.