toning copper pennies coins

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i cleaned the penny with wax,to get off the brown stuffand now it has turned silver.

 

Wow, I can't believe (I do believe it though) they let you play with mercury willy nilly. That stuff is TOXIC. Lol.

 

I have two words: silver fillings

I guess if you don't eat a tunafish sandwich after having a silver-amalgam tooth filling installed you are OK.hya:

 

the penny,is a 1959...so i think its all copper,why did it turn silver...

 

Has your mother been retorting mercury ore in the oven? :mouth:

Either that or you have kitchen poltergeists doing mischief.

 

guess you dont know...huh.i did it on a piece of foil,could that have done it.:headbang:

 

I guess you haven't eaten any king mackeral lately.

 

You probably accidently artificially toned the coin when you heated it in the oven. Heat does funny things to the color of coins. You can produce thin oxidation films of different colors by heating coins and they can take on different characteristcs depending on what is in the air around the coin when it is heated. For example, below are pictures of the same coin being heated in the presence of copper. The pictures were taken approximately every 10 seconds as the coin was being heated. Notice how the color changes as the coin is left on heat? That's cause the thermal oxidation film is getting thicker.



This is called artificial toning or accelerated toning and is looked down on if it is done to fool people into thinking the coin is more valuable. Coins can also tone naturally over time due to interactions with atmospheric sulfides or other chemicals that the coin gets accidently exposed to. For example, here is a picture of a naturally toned lincoln cent where part of the coin has toned silver.



As for cleaning and retoning a copper cent here is a link to a kids experiment page that shows you an effective way to clean pennies http://www.infoage.org/webpages/kexperiments.html
Just be sure to rinse the pennies with running tap water after you clean them with this technique or they will turn green from the salt residue.

To make the pennies brown again, just get some vaseline and sulfur. You get about a gram of vaseline and thoroughly mix in a tiny amount of powdered sulfur (available at the drug store called Flowers of Sulfur). You want to use an extremely small amount of the powdered sulfur or the coin will turn almost black. Well, anyway, you thoroughly mix in the sulfur powder into the vaseline and then take a little bit and rub it on the coin. When the coin starts to turn brown, wipe off the excess vaseline with a paper towel. Then wash it with soap and water or wipe it off with rubbing alcohol. It will turn brown right away. If it turns too dark too quick, just take a little dab of the vaseline/sulfur and mix it into another gram or so of pure vaseline to dilute it out and try again on the next one. The coin turns brown because a film of brown copper sulfide forms on the surface of the coin.

Just don't use these techniques to try and make coins look more valueable than they are with the intent of selling them. You will just end up with a bad reputation if you do and noone will trust you. It is perfectly fine to experiment to gain knowledge of chemistry and metallurgy though.

Also, have fun, but be safe. Only do these kinds of experiments with adult supervision.

 

i will tr ythat this weekend thank you.

 

Kendra,
Aren't you glad you started this thread?You'll be able to write a book when we're done..:rolling:

 

its so much more fun to pour nitric acid on them. And then you never have to worry about selling them fraudulently since it will become a puddle of bluish liquid in a Pyrex glass.

Ruben

 

my mom can not find the sulfer in any drug store,can sulfer from matches work the same.

 

Try a health food store, or chemist they might have some :thumb:

De Orc

 

well well well,that didnt work to well,any other ides.:headbang:

 

Ficsher Scientific

 

what does that mean..............

 

Eckerd's has Flowers of Sulfur. Or you can order it online at http://www.medichest.com/sulfurpowdersublimed-4365.html

 

i have been told that sulfer turns the coin into rainbow colors,intead of making it look brown.:rolling:

 

Very small amounts of sulfur compounds will turn a coin different colors, especially if vaporized on a coin. If you apply sulfur in vaseline directly to a coin it will turn brown if used sparingly and to black with a dark blueish tint if applied too much.