Gold and Silver

I go to a lot of auctions where a lot of junk is sold. I frequently
get jewelry and other items that contain gold and silver. Some will
be marked as to content but sometimes things appear to be gold or
silver but is not marked. Most appears to have no gold or silver
beyond plating.
I plan on getting a kit containing acids and a testing stone for
determining if an object contains gold or silver. Some of the kits
contain needles also.
Am I on the right track and are the needles worth the extra expense?
Thank You for any information.
Roy
Reply to
Roy's Junk
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The test needles aren't necessary for you to determine if an object is gold. All they do is help determine the gold content. You can determine if an object is gold or not by a simple nitric acid test in most cases. Owning the needles, and understanding how to use them correctly, could help you in determining the value of an object based on its gold content, and do so without any destructive testing, so long as the item is solid gold alloy, not gold filled.
You will encounter gold filled that may or may not be so marked. In a case where an object tests gold on the surface, in order to determine if it is gold filled, you should file a notch with the corner of a file, then test the very bottom of the notch to see if it reacts with a tiny drop of nitric acid. If it's gold, the metal beneath the notch will not yield a reaction. If it's gold filled, it will turn your testing solution greenish blue, assuming the base metal is a copper alloy. Gold, if 10K, will slowly turn a brownish color, but higher content gold alloy (14K or better) will generally have no reaction at all with nitric. Dental gold is almost always good to buy, considering it often contains not only gold and silver, but the platinum group as well.
There is a solution that you make that yields a blood red reaction when testing silver. It reacts thus only with silver, so it's a good way to determine if an item contains values or not, but like gold filled, you must get past the surface to determine if the item is plated or not. Base metals typically yield the greenish blue color of copper based alloys when testing, even when the base of some items appears to be silver. Flatware is a good example. The base metal is formulated to be very similar in color so when the plating wears off the flatware still looks reasonably good. The test kit that includes the test needles should come with the indicator reagent for making the test solution. It will be a bold orange-colored crystal in a small bottle.
Be cautious when buying until you know what you're doing. Things are not always as they appear, and at first it's very easy to pay for precious metals when you're getting junk. A 10K gold class ring for 25 cents is a killer good bargain, where a dollar for a gold filled ring is likely more than it's worth. Gold plated objects are rarely worth buying at all. The gold on gold plated jewelry is often only a few millionths thick, so the base metal is likely worth more than the gold. Older gold plated electronic items, especially from WW II era, can be worth a considerable amount, but you're likely to not encounter much of that stuff. It's also not easy to strip the gold on such items, and dissolving the base metals with acid is often not an economical approach due to the base metal thickness, or the low gold content on items such as pins in connectors.
Bottom line: Buy the kit that includes the test needles, then study the proper use, testing against KNOWN objects so you clearly understand the reactions. The bottles in the kits that have daubers as a part of the stopper make testing real easy.
You're going to have a difficult time buying the necessary acids to prepare the test kit. While you won't need a large volume, you will need two acids, hydrochloric, and nitric. A pint of each would be plenty. A reagent grade is suggested to avoid cross contamination of the acids, which can mask or alter proper reactions. Be sure to wear gloves and eye protection when handling the acids, and work outside with the breeze at your back or side. Don't handle the acids in your house, where the fumes, especially from hydrochloric, will start rusting anything that's iron. They're also real hard on your lungs.
Harold
Reply to
Harold & Susan Vordos
first, do you know how to use the acid and stone?? if not then go to a jewelry store or place that buys jewelry, like a pawn shop and bring the kit with you and if they are not busy ask them to show you how to use the kit... you can bet a pawn show knows how to use it.........
Reply to
jim
Thank You for the suggestion. The kits come with instructions.
Your experience with pawn shops must be better than mine. : )
I have always found them overpriced, unfriendly and seemingly geared toward people that need money bad and are not too concerned with cost or value.
It may be I have just been in the wrong ones.
You in that business?
Thank You
Roy
Reply to
Roy's Junk
Another method to consider is the calculation of specific gravity.
This is by means definitive - it won't, for example, help much with pieces designed to deceive, such as lead-filled, or if there are stones attached - but it is a really good starting point.
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Its also non-destructive, perfectly safe and non-toxic, portable, reasonably inexpensive (accurate scales are
Reply to
A.Gent
For a qualitative test for gold, all you need is nitric acid in a glass bottle and a glass rod to apply the acid to the object to be tested. If it turns green, it is not gold, if it does not turn green it MAY be gold.
I say MAY be because it could still be gold filled or gold plated. So if it does not turn green you need to file through the surface and do the test again.
For a quantative test, you need the various testing needles and a good touch stone. And the knowledge how to use those. This will help you determine the value of a gold object.
Good luck.
Be very careful with the nitric acid.
Abrasha
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Reply to
Abrasha
Lead is a bit lighter than gold IIRC. There are a few things heavier, most very expensive. Tungsten and uranium are about the only things cheapish and similarly dense, mercury too.
Reply to
Ian Stirling
I've included a table of most interesting/relevant alloys at
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is a *lot* lighter than gold. Equals roughly 10K gold.
Reply to
A.Gent
It's more involved than that, too. Troy ounces are larger than avoirdupois ounces. Troy ounces are 480 grains in size, avoirdupois ounces are 437.5 grains in size. 5,760 grains = 1 troy pound, 7,000 grains = 1 pound avoirdupois.
Harold
Reply to
Harold & Susan Vordos
Ah, but are we weighing it in troy or avaudip auvid bah... however-you-spell-what-we-call-"regular pounds" pounds?
Just had to throw my monkey-wrench into the works :)
Reply to
Don Bruder
That's only true when it's being used like a verb...
Potential customer: So how much is it gonna cost?
Mob Enforcer: I charge by the pound.
Potential customer: Oh. That might be expensive, then. The guy I want you to beat up is about 200 pounds.
Mob Enforcer: You misunderstand. A pound with a fist is cheaper than a pound with a hammer, and that's cheaper than a pound with a baseball bat, and a pound with a telephone pole is more expensive than any of those. That's why I charge by the pound. So whatcha want I should pound 'im with?
Reply to
Don Bruder
All of this "discussion" should explain nicely why the metric system is so much easier. :-)
Abrasha
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Reply to
Abrasha
snip----
For everyone except for us old goats that know the old system so well. I have no trouble converting, or otherwise keeping it straight, but still struggle with the metric system, if for no other reason, I still have no real reference as to sizes and volumes. Not until I convert to the systems with which I am so familiar does it come in clear focus. I guess it's all in what you get used to.
Yes, I agree, the metric system is superior.
Harold
Reply to
Harold & Susan Vordos
"My car gets 50 hectares to the hogshead and I like it that way!" - Abe Simpson
Tim
-- "That's for the courts to decide." - Homer Simpson Website @
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Reply to
Tim Williams
What you need to do is to develop an eye.
And grow balls.
Thing is, you show up at an auction with a chemistry set and .... let's just say it won't be pretty. And I'll lead the charge if my O'l Lady doesn't nut shoot you first.
Dumbass, you have to learn the stampings and other stuff. If you don't want to put in the effort to learn these things, and it applies in more than an auction setting, your ass is dead meat.
You show up at my auction and scrape a stamped ring .... Your ass is mine.
If you can't tell the difference you have no business being there.
Reply to
Mark

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