Found a coin from 1714 at a flea market in Boise, cleaned it too fast, oops
So I was digging through a bin of old junk at a flea market last Saturday and spotted this tiny silver coin stuck between some rusty keys. Paid 3 bucks for it. Got home and looked closer, it had a bust on it and some letters I could barely read. Turns out after some careful internet searching, it's a Spanish colonial coin, possibly from a shipwreck mint. I was so excited I scrubbed it with soap and a toothbrush like an idiot. Bad move. I read later that cleaning coins can wreck their value and the patina. The details are still there but it looks kinda dull now. I'm kicking myself. Has anyone here ever messed up a find by cleaning it? What do you use to safely preserve old coins without damaging them?