im curious to know how sunlight may effect coins,would it improve the look or ruin it or no diffrence.is there a case for leaving a coin in direct sunlight.would the patina get lost.would it give it nice toning.just wondering how it would effect the preservation of coins.Ive heard none mention about it before so thought i would ask.
Never known any light source to have an effect on metal objects. One thing you do want to guard against though, is overheating. High temperatures can cause coins to darken.
I would avoid direct sunlight if for no other reason than the heating effect it would have. The British Royal Mint and Franklin mint used to warn about leaving coins in direct sunlight. I've never seen much basis for concern but have seen few coins exposed to much sunlight.
Sunlight will definitely change the coin - and not always in a positive manner. Just sit any coin on a windowsill for a day or two - you'll soon see what I mean
