Ageing gold coins

Taikonaut

Hi, does anyone know of a proven method on how to accelarate toning on gold coins that looks a bit clean? I heard sulphur and egg yoke are sometimes used but I have tried it and it makes no different.

mhammerman

Just a thought with some opinionated viewpoints...

Don't play with your gold surfaces. Gold doesn't tone but the color is affected by the amound of copper and silver that is found in the base ore used for the planchets. The colors on old gold range from a green cast to a deep orange to bright gold. This is the variation you see in old gold and it is from the base metal, not toning. Old gold sometimes has spots and this is not uncommon and it comes from a concentration of copper in the ore. I have seen other spots on gold like this one...http://www.heritagecoins.com/common/view_item.php?Sale_No=369&Lot_No=1179 but I don't know the source or cause of the spots and defer to one of the more astute gold collectors that post here.

Egg yokes and sulphur...not good. Have fun!

vega1

I *really* wanted to make a comment that putting them in a wooden cabinet might do the trick. I'm sorry

In any case, I must say that in my humble opinion any effort to intentionally "accelerate" toning on a coin is considered artificial toning, and depending on how it is done it could irreversably harm the coins.

I am certainly no expert on gold, and it is not in any way my business what you do with your coins of course. However, if there is one thing I have learned over the past couple years from this forum, its that you should never mess with your coins in this fashion or very bad things may happen. Just my opinion though.

By the way, I also found mhammerman's post to be very informative.

nwcs

The gold won't tone. it's the copper. And how reactive the copper will be will depend on the alloy's mixture. Personally, I do not think that accelerating toning is a good practice.

SFDukie

What they said!
Seriously- I feel that artificially toning coins is a bad practice. First, as described above by folks more knowledgable than I am, gold doesn't really react (ok chemists, that is a gross oversimplification...). But even for silver, which does react, I think it is harmful to the coin and may decrease its value (at best) and is an attempt to deliberately deceive (at worst)
If you do a search on artificial toning you'll come up with lots of info, including that on gold toning.
PS Do you follow the Chinese space program?

mhammerman

Results on a search on "toning gold coins"...

"Gold -

When first struck, gold coins are a bright yellow-orange color. As gold coins are not pure gold but are alloyed with copper and traces of other substances, they do tend to tone over a period of time. Over a period of decades, a gold coin will normally acquire a deep orange coloration, sometimes with light brown or orange-brow toning "stains" or streaks in certain areas (resulting from improperly mixed copper trace in the alloy). Light toning does not affect the value of a gold coin.

Very old gold coins, particularly those in circulated grades, will sometimes show a red oxidation. Gold coins which have been recovered from treasure wrecks after centuries at the sea bottom will sometimes have a minutely porous surface because of the corrosive action of sea water. Such pieces sell for less than specimens which have not been so affected. Care must be taken to distinguish these from cast copies which often have a similar surface.

Now that we've determined the forces that can change the natural planchets of a coin, we have set the foundation for distinguishing between artificial and naturally toned coins. In our experience, the majority of unnatural toned coins is easily detectable. However, as the reader will further read , the coin doctors are also aware of the information. That's why the interview with one of the so-called "coin doctors" shed even more light on a very complicated subject. "

Taikonaut

The most successful I have found with regard to toning a coin be its gold or copper is sweat, the squash penny in your hand when you were a kid tend to be the one that develop a patina quicker than the one that is left alone.

relayer

mozin

<< <i>Hi, does anyone know of a proven method on how to accelarate toning on gold coins that looks a bit clean? I heard sulphur and egg yoke are sometimes used but I have tried it and it makes no different. >>



I knew an old coin shop owner that used an ordinary floodlight/spotlight. He mounted the light socket to a small board so the light stuck straight out from the board. He layed the board on a flat surface, placed the gold coin on the now upright bulb, and plugged in the light cord. He flipped the coin after some time passed and continued this until he liked the look of the coin. If the gold coin colored unattractively it got a quick dip/rinse/dry and back to the light bulb for another try.

I saw a number of his gold coins before and after, and the after looked better. Whether or not the grading services would call it artificial toning is up for discussion.

magikbilly

<< <i>I *really* wanted to make a comment that putting them in a wooden cabinet might do the trick. I'm sorry

In any case, I must say that in my humble opinion any effort to intentionally "accelerate" toning on a coin is considered artificial toning, and depending on how it is done it could irreversably harm the coins.

I am certainly no expert on gold, and it is not in any way my business what you do with your coins of course. However, if there is one thing I have learned over the past couple years from this forum, its that you should never mess with your coins in this fashion or very bad things may happen. Just my opinion though.

By the way, I also found mhammerman's post to be very informative. >>



I agree, especially with that wood box comment I wondered yesterday in that post about a similar comment - that gold coins didn't tone was said to be proof wooden boxes are safe.

Billy

Taikonaut

Not all coin cabinets are equal and its certainly true the one I use to store my coins are very good at resisting acid attack, corrosion and toning, the material use to make the cabinet keeps harmful element to a minimum hence the reason its being used by museums. All my coins I store there looks pretty much the same as it did when it first went in many years ago and compared favourably with coins I stored in paper coin envelopes inside dry cardboard box, a proof gold I have there is still free from toning after 2 years and certainly in better condition than a 2 year old proof gold sealed in a PVC holder by the mint which already showed clear sign of discoloration.

As for creating tone or patina on coins I realise that if you place coins on the window sill it tones quicker, this makes me wonder if sudden variation in temperature especially in the UK were the climate is very moist can accelarate toning. Also living near the coast silver tarnishes more frequently than on shore.

clw54

It's sad how much tampering is done with coins to squeeze a few extra dollars out of somebody. Not surprising, but it is sad.

boz

mikebombs

Can someone explain why the ms coin in my sig line is so dark it almost looks proof? In 1908 no half eagle proofs were made. What would make the coin tone this way?

mikebombs

magikbilly

<< <i>Not all coin cabinets are equal and its certainly true the one I use to store my coins are very good at resisting acid attack, corrosion and toning, the material use to make the cabinet keeps harmful element to a minimum hence the reason its being used by museums. All my coins I store there looks pretty much the same as it did when it first went in many years ago and compared favourably with coins I stored in paper coin envelopes inside dry cardboard box, a proof gold I have there is still free from toning after 2 years and certainly in better condition than a 2 year old proof gold sealed in a PVC holder by the mint which already showed clear sign of discoloration.

As for creating tone or patina on coins I realise that if you place coins on the window sill it tones quicker, this makes me wonder if sudden variation in temperature especially in the UK were the climate is very moist can accelarate toning. Also living near the coast silver tarnishes more frequently than on shore. >>



Comparisons to PVC are not the best. Brazillian mahogany is not African mahogany, and neither are good for metal storage. Not to mention felt, adhesives, finisghes, glues etc. which all have harmful potential. This is not just my opinion - if you search for "wood" you will find many, many papers, and then more papers, that I have posted in this forum addressing this very fact - especially compelling are those by and for museums that explain why wood is not suitable for storing much of anything, especially metals.
This is like in painting - there are many "painters" and "restorers" that practice "the old methods" (lots of oil, resins and other injurious nonsense) - in direct contradiction of the science being done on the works in question which show very little/no such materials were used. Like how so may think Rembrandt or Vermeer used resins to achieve what they did - not understanding that the transparency they are seeing is not resin but the result of several hundred years passing and changing the refractive index of the linseed oil binder making it have that wonderous gem-like lumious transparency.

Best,
Billy

Taikonaut

I have to disagree with you on some of the reference you are making with regard to wood being harmful to metal, it depend how the wood is prepared and what sort of wood is being used. The trays used are very dry mahogany compared to the caseing and first hand experience I have witnessed it hardly does any harm to my coins, it doesnt matter what all those scientists are telling you and what sort of tests they done in their own lab Peter Nichol's cabinet was thoroughly tested by conservationist to be totally fine and I can vouch for that, also the paddings are not strictly felt but soft cotton thats been flattened into a cloth and cut out into circular discs that is used here. As a collector of Japanese swords for many years and guranteed by leading authorities in the UK, US and Japan we can categorically say they have use specially dried wooden scabbad to house newly polished blades for centuries, if wood was suppose to be harmful to steel they would never had used it. Sword guards or tsuba's and other metal ornaments are also housed in attractive dried out wood very similar to the mahogany coins trays in my cabinets, though having said that I believe there are many other cabinets which uses wood that does harm metal so there is important merits to your report.