Restoring a coin. What type of damage is this?

"As long as it's silver sulfide." Aye, there's a rub but the method sounds solid.

It's probably a little complicated for a beginner though.

 

Log in or Sign up to hide this ad.

No form of appropriate coin conservation is for a "beginner."

 

Good point but I was a beginner at one time.

Someone gave me good advice and told me to practice on something that won't hurt much when I ruin it.

I still ruin something every now and then.

I shy away from touching very valuable coins for this reason.

 

The point being that it isn't a high value coin, but a conversation piece that he wanted to spiff up.

 

Which part is complicated, boiling the water or adding the baking soda?

 

To me, as a (literally, it's hardwired) obsessive practitioner of the dark art, the idea of suspending a coin in a baking soda solution is rather like discovering a spider crawling on me. Even if you tell me it's not a colloidal suspension I won't believe it. And boiling water moves (convection), so that was out of the question. It was only when I thoroughly mixed the solution first, and baked it in an oven to an assuredly constant temperature throughout to minimize convection, that I was able to begin achieving results which both satisfied me and kept away the heebie-jeebies. I experimented with single layers of foil and turning the coin, flapjack style; sandwiching it between perforated foil layers; aluminum screen; thicker sheet aluminum; pure aluminum pans; you name it.

Dirty little secret: all of them work, more or less.

 

It's not a colloidal suspension...

 

ROFL. OK, question: Why does salt dissolved in water still taste salty?

 

#1, which salt? Sugar dissolved in water tastes sweet too, so?
#2, a colloidal suspension is defined by the particle size of the particles IN SUSPENSION. You can tell a suspension by shining a light through the system in question. If it is a solution, the particles (ions) are too small to scatter the light and you won't see the light path. If it is a suspension, it will reflect the light and you will see the path of the light.

One proviso, make sure the sodium bicarbonate (NaHCO3) is REALLY dissolved before doing the test. I'll look for some pictures. If it were a suspension, I would agree with you.

 

I was under the understanding that NaCl completely dissolves - it literally gets rendered asunder molecularly - in water. Always wondered why it retained the taste if that's true.

 

Tell that to the US Mint.

 

or the BRM, the Perth, the Austrian, the Australian, about a dozen Pacific Island nations, and maybe worst of all, the Canadians.

 

@Alacrity
I can at least be more casual with them, knowing that the only value in the artwork is sentimental value. That will make it easier to put them in the display case.

And every time you view the coins know Grandma had you in her heart, the fact that she thought she was investing in something of value for you means more than all the tea in China. What a nice keepsake!

 

Good point, you can't taste NaCl, because as soon as it dissolves (even in the saliva on your tongue) it is Na+ Cl- . Now I can't put any Cl on your tongue, but would you like to try some Na?

 

I'll take your word for it. You're the chemist.

 

Actually one of the dictums in chemistry is that the properties of a compound are not related to the elements that go to make it up.

 

The same could be said of children.

 

Rick and Morty is my new favorite show