My 1912-S Lincoln Wheat Penny

Sorry Paul, you just completely ruined a $40, semi-key coin. Peroxide is the absolute WORST thing you can subject ANY coin to.

Let this be a lesson to you all on how to NOT properly conserve a coin. Proper conservation is a scientific process, not randomly soaking coins in various solvents to "see what happens". If you're not fairly certain of what the outcome will be, DO NOT DO IT! It's better to have a dirty grimy coin rather than an improperly cleaned piece of dung.

good old ms-70 and e Z Est and on copper prob some dahlers darkener might be needed.....

If and when I find some reagent grade acetone and xylene, I'm going to post a series of tests like this in hires x5 images (new Canon T4i with an MP-E lens!).

I've spent hours reading anecdotal stories with too little facts. I can't believe nobody has done this yet, there are just bits and pieces all over the place. It should be pretty simple to get 50 or so of the same non-key 1950-ish (brown) and 2010-ish (red) Lincolns in about the same condition. Then do timed, temp, measured tests with a collection of chemicals, reagents and fingernail polish remover, H2O2, olive oil, tap water, Verdicare, the polarity ladder, etc. Image before and after 5/20/90 second and 1-24 hour treatments of each.

Can't be that hard, can it?

And thanks for your concern, BadThad, but may I respectfully suggest that you might read the post before expressing your disdain. Perhaps that is a little lesson for you?!

Thad, ok, so WHY is peroxide so bad? What does it do to the penny?

Not a lesson, just a failure to read all the posts.

I just don't want noobs reading and following some of the appalling suggestions I've seen in this thread.

The H2O2 explains that this solution is sort of top heavy with Oxygen. Oxygen is the first thing that attacks Copper and does so readily. If you read the posts about coin cleaning, cleaning coins, Acetone and all the other similar posts available by using the Search Tab at the top, you sould see or should many discussions about most of this.
There is possibly many, many items people claim they have used or read that someone used on coins with only great or OK success. And possibly some are true but more than likely what you read on the internet is from people that really just guess, repeat something someone else said or make it all up.
Over the years I've read about Baking Soda and water, Orange Juice, Tomato Juice, Olive Oils, Spit, Nail Polish Remover, Acetone, Laquer thinners, Mineral Spirits and on and on and on. Such experimentation is fun but shouldn't be attempted on a coin of a value over face value. And even then it could be the ruining of a coin for someone in the future.
It is not smart to sand down a 500 year old table. It is not smart to rewrap a 2,000 year old Mummy. Nor would it be smart to run King Arthurs Sword accross a bench grinder wheel, it there was such a Sword. As a general rule it is always best to let sleeping dogs lie. Old saying.

Agree.......although....there are ways 8).......