Anybody know about spectroscopy with a diffraction grating and the
naked eye? I've had success recognizing simple atomic spectra
(copper, zinc, mercury, and the ever-present sodium, for example) and
even a few more complex ones like iron and xenon.

I have MIT Wavelength tables (1939) and some Grotrian diagrams, but
there are still some alloys I have not managed to identify
spectroscopically.

I am wondering: is it possible to identify all the naturally occuring
elements with the naked eye? Also, how accurate are the intensities
in MIT WT, and how accurate is the NIST Atomic Spectra Database?

PS. Anybody interested in some hand-drawn Grotrian diagrams?