QUESTION Silver buffs?

saintguru

Please explain to a Gold-guy this...why do silver coins tone in rainbow colors yet silverware and other objects tarnish black? It it an allot that is added to the coins for hardness??

airplanenut

It has to do with the environment... plenty of silver coins will turn black in certain conditions. Many coins, though, have been exposed to the right chemicals for the right amount of time, causing them to turn rainbow colors. If Wayte Raymond made a fork board, and a set of forks sat in it for a few decades, you'd have monster rainbow forks.

Jeremy

100proof1957

well, silver ware is .925 fine a lot of times and i think coins are .900 fine,the alloy must have an effect.

saintguru

I would guess it's an alloy thing too. That is what accounts for the rare but not impossible color toning in Gold coins....10% copper alloy.

techeff

I love toned gold. This one's got the blues...

LanLord

Creative chemistry

saintguru

Come on...WHO KNOWS????

cladking

It's probably largely the luster. The surface is packed closely on a struck coin where
silver ware is more like a cleaned coin. Silverware will turn rainbows sometimes.

LindeDad

Could also have to do with the cleaning of silver ware after use. What chemicals are in soapy water? I know for a fact that many soaps contain lye and who knows what else.

Bootleg

also if let sit in a damp place for say 20+ years in the old whitman folders in a old lock box,the air also tones coins,also another is if they are in the old old card/PVC type holders.........

MORGANHUNTER2

Silverware tarnishes due to the rapid oxidation on the sliver from non use, and the fact that without cleaning the silverwate will keep tarnishing even when washed in a soapy substance. Most flatware has a composition of 60% copper, 20-30 % nickel or platinum based metal and the balance is silver for the hardness and obvious shine. I have a set that was my grammies from the early 50's that has not been used in well over 20 years- it looks brownish black, all it needs is to be polished and it will look as if new. And its a full set for 16- worth a few bucks, so i've been told.

Dabigkahuna

I've noticed that a lot of "cleaned" silver coins get that black tarnish tone. Maybe wear is the key?


Larry
Dabigkahuna

saintguru

MAN! I though the answer was going to come shooting back...clearly there isn't anyone that knows definitavely...YET!!

lordmarcovan

<< <i>why do silver coins tone in rainbow colors yet silverware and other objects tarnish black? >>



Well, alloy and a number of factors have to do with it, of course, but it's also a matter of degrees. Silverware goes through the rainbow stage before it gets black.

I just got some new S&P shaker caddies here in Room Service (yes, we use real silver-or silver plate, anyway- in a 5-star resort). They are new and I took 'em out of the box but the plastic bags inside were not always wrapped around them perfectly, so the tissue paper that was also in the boxes toned 'em. I have some "monster toned" salt and pepper sets!

I found myself thinking, "Cool, they're really pretty!", but a coworker saw them and said, "Ahh, man, look... they're brand new and we already have to send 'em to the Silver Room!"

You should see the big silver coffee urns we put out for breakfast. We use Sterno to heat them while they're out in the lobby, and they come back with all kinds of pretty lavenders and sometimes pale orange tints. Too bad "monster toning" hasn't caught on in foodservice like it has in numismatics!

The ceiling medallions that the light fixtures in the hallways hang from are also silverplated. Housekeeping only gets around to cleaning them once in a very long while, so I like to look up as I walk down the hall and rate the eye appeal of each fixture.

saintguru

LM...still a "weak" explanation...there has to be a definitave answer..I still think it's the alloy but I want to know...

Conder101

Yep, LM has it. It's just a function of time. The higher silver content of silverware will cause it to tarnish faster but it goes through the "rainbow" stage as well. The colors seen are caused by the differing thickness layers of the tarnish. When the tarnish gets thick enough light doesn't pass through it and it appears black. On thinner layers some light reflects from the surface while some passes through and is reflected back from the surface below. The two reflections will be slightly out of phase an will interfere with each other. The color the eye will see depends on how far out of phase they are and that depends on how much further the light in the second reflection has to travel. (Twice the thickness of the tarnish layer.)

White light is made up of many colors. If the tarnish layer thickness is half the wavelength of say blue light the two reflections will be out of phase by the wavelength of the blue light and it will be canceled out. So the light you see will be missing the blue light and the human eye will see it as blue. (It's kind or paradoxical, the mind "sees" a color in reflected light if it is missing.)

topstuf

Sterling flatware tones in colors like coins.........and like Conder said.
So do sterling Franklin Mint medals.

AND......even .999 silver coins.

I've handled many 100 oz bars with golds, blues, and black.

Function of the oxidant rather than the alloy. Well, strictly speaking, I guess the alloy has to have SOMETHING to do with it or the oxidant would react identically on all of em.

But....even PURE silver tones. At least .999 pure.

Have never studied "Laboratory pure" silver.

saintguru

HERE'S THE ANSWER....

they were placed in holders or envelopes with high sulfur content that gave the toning...not the silver itself...

TAAA DAAA...whoever alluded to holders was almost totally right...I think the envelopes were really the biggie....they were much more prevalent than holders...

Shamika

.

Jdurg

Pure elemental silver will tarnish just as readily as any other form of silver. Silver reacts quite readily with the halogens and sulfur containing gasses. The other elements in the alloy will only alter how quickly the silver tarnishes. (As other elements will possibly react with other compounds and tarnish, thus changing the type of tarnish seen on the 'silver piece').