Welcome, Allison.

Sorry, I have neither come across a specific word to describe this silvery effect, not have any great wisdom about searching that you have not probably tried, other than the general points:
1. Have you tried googling using wild card expressions?
ii. Have you trawled through the etymylogical resources online (eg, http://www.onelook.com/?w=moon&ls=a ~ including looking at the PIE roots in Bartleby (eg, http://www.bartleby.com/61/roots/IE302.html or places like this: http://www.etymonline.com/
c. Have you tried skipping through some of the riches of online dictionaries, perhaps on specialist subject areas? (eg, see http://stommel.tamu.edu/~baum/hyperref.html#languages)
X. Have you thought about searching poetic interest sites? An example: http://www.poeticbyway.com/glossary.html


If all else fails I expect a bunch of us fools can dream up a few nonce words for you to spear!

edit: hah, well done Jackie! I just hope the research ideas may also be fruitful in other circumstances. Is that word known to others here, btw?

edit 2: hmm, well I see one of us knows it...!!
http://home.mn.rr.com/wwftd/mno.htm#moonglade