Coin Characteristic QUIZ #1

I posted a few posts as this on another forum where I am no longer welcome. Hopefully, we can have some fun and continue the quizzes here.

This is a micrograph (18X) of an Uncirculated Lincoln cent that has toned. Describe what you see in the image to a collector who cannot see it. Does the pattern remind you of anything?

 

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very similar to the patterns on the hide of a giraffe or leopard

 

A dried lake bed

 

Looks like what's left behind from soap bubbles.

 

Beefer518, posted: "Looks like what's left behind from soap bubbles."

THREE GREAT ANSWERS. See easy.

Soap bubbles is the best.

Now, what would cause a bubble pattern of toning?

 

Heat? Almost looks organic

 

poorly annealed planchets

 

I'm going to go with the obvious -

It was cleaned with soapy water (or similar), let dry with soap residue still on it, and the toned was affected by the 'invisible' residue.

 

"bradgator2, posted: Heat? Almost looks organic. It does look organic and has "flow." What would heat do to a bubble?

expat, posted: "Poorly annealed planchets? We know heat can change the color of both coins and planchets. Annealing requires heat. What would happen to a heat pattern on a planchet when it is struck? How do we explain the pattern on the coin?


Beefer518, posed: "I'm going to go with the obvious -
It was cleaned with soapy water (or similar), let dry with soap residue still on it, and the toned was affected by the 'invisible' residue."

This is possible but I was not around to prove it. This coin has an unnatural color for a BU cent. Additionally, the bubble pattern indicates something dried on the coin. I'm going to guess it was some sort of liquid chemical (perhaps even diluted w/water). Anyway, this coin has a CHEMICALLY Altered Surface.

Quiz#2 tomorrow.

 

Very interesting post...hopefully I can catch quiz #2 tomorrow before it gets answered.

 

You should let these run a bit longer. I was going to say a liquid was applied to induce toning.

 

I am glad I hit this one after it was answered. My brain was trying to get much too scientific on me when the whole time it was the simple answer. Cool thread!

 

Well, I am not certain. Would a chemical/soap drying under heat leave a different pattern than a chemical/soap drying at room temp?

 

I would guess yes because the temperature would influence the drying time.

This should be an easy experiment for an interested member to do. Use a Proof Kennedy and put a drop of that hand soap that comes out as a foam on its field. Set it on a counter to dry. Do the same thing with a coin and place it on a Pyrex dish that has been heated so it dries really fast. Take photos.

 

OK, next time. Need to build interest so folks watch for the new Quiz when they are posted. Best when we all let the new collectors go first too.

 

It actually is a scientific answer. The pattern looks very close to soapy or oily water, so it is safe to assume that the pattern was caused by a liquid. As the liquid evaporated, the main drop of liquid broke up into many droplets. Particulates (Probably oils or something) less dense than water, which are floating on the top on the droplets, suddenly have a slope which they slide down. These accumulate and solidify around the droplets, inhibiting toning around the droplets. That creates the pattern you see.

I did a quick little experiment to show this. I had a drop of water, and I added a drop of vegetable oil to the middle. It was immediately shoved to the side and water’s surface cohesion forces pulled it all the way around the water drop.

 

Great post! Keep them coming, just give some of us “slower folks” a little more time to guess!

 

I see the day when we posters will have to pony up a little cash to be privy to dynamite threads such as this. The proceeds will most likely be split on a 75%-25% basis, with CT getting the lion's share and the thread's author the lesser portion. Keep em coming, Insider! Especially while it's still free.

 

It looks like volcano lava.