World of Coins

Collecting coins => Cleaning, conservation and storage => Topic started by: Figleaf on April 15, 2007, 10:01:20 PM

Title: Using pollution
Post by: Figleaf on April 15, 2007, 10:01:20 PM
You must have seen them, those harsly cleaned coins, shiny like Aunt Mildred's silverware and not a trace of patina. Here's my favourite recipe. I leave them on a windowsill for a number of years. Each year, they get turned around. Where I live, the air is not very polluted, but silver coins are back to normal in about 3 years. Copper takes a litle longer to return to milk chocolate brown, but it gets there. I learned this trick from famous Amsterdam dealer Jacques Schulman. Jacques lived on one of Amsterdam's canals and his shinyware got enough sulphur to get back to a normal colour in about a year. The wonderful thing is a) harsly cleaned coins are a lot cheaper and b) you now have an official reason to procrastinate. Just make absolutely sure your loving wife doesn't clean the dirty old coins for you. ::)

Peter
Title: Re: Using pollution
Post by: bruce61813 on April 16, 2007, 05:33:42 AM
That's not a trick, that's how they got to be that color the first time. People assign 'grren' to age, when the real surface color keeps turn darker brown until it reaches a black. The green oxides require water and other chemicals. But this is one of the things I have advised for some time now. It is good to hear others recommend it.

Bruce