I have my late grandpa’s silver spoon attached to my fridge with a neodymium magnet. What kind of chemical reaction causes that discolouration?
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Thanks for the link.
That just doesn’t explain the reaction between the two metals.
silver needs hydrogen sulfide to tarnish, although it may tarnish with oxygen over time. It often appears as a dull, gray or black film or coating over metal.
Somehow the silver got colourful instead of the usual grey.
There are multiple examples of the colorful toning in the article I linked. So you appreciated the link, but not enough ot actually look through it.
Pictures of tungsten tarnishing aren’t helpful when op is talking about silver. Stating “thank you, that’s the general idea yes, but I was trying to ask more specifically” isn’t an attack on you. You don’t need to defend yourself.
Right below the picture of tungsten is this picture of a silver dollar.
That is a surprisingly not blue tarnish, if its supposed to explain what OP is showing us, if it makes a point, please help me comprehend.
I do see that the light has mostly obscured a small band of blue so maybe its at a really neat phase of tarnish, but that’s speculation and this photo provides no evidence that is actually the case. Either way, I really dont think the tarnish article goes far to actually explain the blue aside from describing the mechanism.
That is a surprisingly not blue tarnish this photo provides no evidence
Reading comprehension… What even is it?
I do see that the light has mostly obscured a small band of blue so maybe its at a really neat phase of tarnish, but that’s speculation and this photo provides no evidence that is actually the case. Either way, I really dont think the tarnish article goes far to actually explain the blue aside from describing the mechanism.
I read everything. (Even changed to my mother tongue.)
Didn’t find anything about interactions of different metals. It only said something about interactions of metals and non-metals.
This is why there was always a butler polishing the family silver.
Because they had no aluminium foil back then…
It’s oxidation, so rust. You can clean it with silver polish.
To be pedantic, rust is explicitly iron oxide. Iron rusts, silver tarnishes.
Generally it’s silver reacting with (trace) amounts of sulfur containing gasses in the air to form silver sulfide.
Silver sulfide isn’t blue, but the colours, and especially the multiple hues are caused by thin-film interference. That’s the same effect that gives soap bubbles that shifting multi-colour effects.
The only way to remove it, is by grinding off a tiny bit of material, which is what you do when you polish it. The tarnish doesn’t go further than the surface layer, so it’s actually a pretty amazing way to preserve the metal.
Fun fact: if you ever want to make silver look old, put it in a closed box or bag with a hard boiled (or rotten, but I suggest boiled) egg. Those are high in sulfur compounds and will add months of tarnish in minutes.
I’d use a pencil eraser to polish off surface level tarnish, no need to bust out the grinders here. But otherwise your comment is on point.
He’s not saying use a grinder. He’s describing polishing as micro-grinding.
Why did it spread from the magnet?
Not sure what exactly that means.
There’s another magnet below to hold the other metal sign. The stainless steel fridge looks fine.The 800 means it’s 80% silver. The other 20% are mostly copper.
The other symbols are maker’s marks.
800 silver discolors faster than 925, but it’s harder, cheaper and better for daily use.
Silver needs to be polished every so often
Something like this will fix 'er right up:
Could be caused by whatever coating is on the magnet, I tried to see if sulfur could be a component of a coating but gave up. Maybe others will just know.
That would make sense. I searched for neodymium coating and found that they’re often coated with Nickel-Copper-Nickel or Zinc. 🤔
