During this mild washing and rubbing, there was minute debris on the coin as you moved your fingers or whatever you used, definitely damaged the coins surface, what part of this don't you understand?
It does not. All debris gets wash away restoring luster that is covered by old debris. Read the quote from my previous thread. The metal composition of cu-ni is so hard that is must overcome its high and low resistivity pressure to cause damage. Now there is also some data on this. No YOU don't get it.
It is also for the same reason why CU-Ni (copper and nickel) was chosen to be the metal composition for coinage application because of its toughness, resistivity to corrosion.
OK, and you're the person who is saving ALL their quarters. I AM a chemist and can tell you with a large degree of certainty that most chemists won't know squat about coins and "conservation".
Did I say that a chemist know a lot about coins? whats a matter with you people. This is just a post of my own perspective. That is all. I'm not challenging any of you. You people are terrible.
What is my position of collecting quarters got to do with this particular discussion..? What is that matter with you? You can't even hold a rational reasoning. Get lost. You are ignore from now on.
"High and low resistivity pressure"? Word salad. What must overcome its... whatever that was... to cause damage? "Appeal to authority" is a logical fallacy. If the "authority" you appeal to is someone we've never heard from before, and you can't coherently report what she's trying to say, it's also really ineffective.
No, you're just saying that we're all wrong, and then pretending to laugh dismissively at us. Except that instead of dismissing us, you keep coming back to argue.
If you are worried about the dark stuff in the crevices of the design, Leave that alone. If they were dug out of mud, then a soak in soap and water is fine. No scrubbing or digging at them with toothpicks.
I'd add "don't forget to rinse thoroughly". If they're dug out of mud, you're starting at a disadvantage, but there's no point in leaving soap residue. Pure soap or detergent probably won't react with the coin, but scenting agents are another matter.
What you say makes a lot of sense. Almost no matter what agent you use to clean a coin, if you leave residue, it will end up making it look worse than you started from if the residue reacts with the coin or the environment.
There is a vast difference in hardness of the outer nickel layer on such a coin compare to 90% silver 10% copper, also chemical reactivity , and other factors. What type of microscope did she use to compare surfaces? 30X stereomicroscope or even better a SEM? The naked eye can not detect such damage, but under magnification, even 10X , it can be seen if one knows what they are looking for. Jim
What did she use as a reference to quantify the luster changes. Since there aren't really any quantifiable standards, I'm assuming this was done subjectively and based on her experience evaluating luster on high grade coins