Information about Gold

[Nad]

Rudy, the rust,or black color is due to a gold / sulfur /iron bond..A bit of hydochloric acis should solve the color problem, cordially Nad

[drparlayy]

Hello, I am a newbie, how do I know if a piece of jewelry I have found is gold, or silver and not just plated?

[Rudy]

Originally Posted by Nad

Rudy, the rust,or black color is due to a gold / sulfur /iron bond..A bit of hydochloric acis should solve the color problem, cordially Nad

Yes, I agree. If you look at my post, I was referring to rust, which is an oxide.

[bmc94]

that's interesting good information

[DIGGER27]

Thanks Carol!
This info will come in handy when I find that first gold target.
Hope it happens soon, the girlfriend is getting impatient!

HH

[ToddB64]

Hi Carol !

When my wife's father passed away recently, we inherited a few pieces of his jewelry. One piece is a gold chain marked "Made Italy" on one end of the clasp and stamped 417 GS on the reverse side of the same clasp-end. I know the 417 means 10K and assume the G means Gold, but can you tell me what the S means ?

Perhaps you will want to add GS to your chart posted 04-11-06, as I didn't see any mention of it on the three pages of this thread.

Thanks,

Todd

[Metal-Magnet]

I've saw on pawn stars them scratching gold on some kind of pad and putting some type of liquid on it. Anyone know of this method?

[Adirondack AL]

Originally Posted by Metal-Magnet

I've saw on pawn stars them scratching gold on some kind of pad and putting some type of liquid on it. Anyone know of this method?

Yes, it's an acid test to see if it's gold and what the purity is.

[vivsfindings]

Due to the cost of gold, bold pieces are expensive and harder to sell. Therefore, in order to make them more affordable, jewelers have been making many of those bold pieces but hollow. They kept the look but not so the gold content nor the quality to sustain use and wear.
So what happened? Because they were hollow inside, the jewelery would ding, get poked, slits, and even brake pretty fast and easily within first days of use.

They have come up with a solution and is to fill that hollow space with a sort of resin. As far as I know, this new technique has been recently introduced by the Italian jewelers. Don't know yet if and what kind of marking or stamp those pieces will have. But things are that will in fact be gold, pass the tests, only thing that the nice weight on that gold ring won't be all gold but resin covered in a thin sheet of gold.

I'll keep you posted should I may find more info about it.

[chrispua]

There's also 23k gold stamped 23 kdm. KDM stamp which means that the Jewelry was soldered with Cadmium. I found a gold bracelet with that marking some time back, did a check on the net and found the above info. Most likely the gold bracelet originated from India.

[KingTotsalot]

Originally Posted by Metal-Magnet

I've saw on pawn stars them scratching gold on some kind of pad and putting some type of liquid on it. Anyone know of this method?

This is a long time common method for testing gold. But it comes with some caveats.

First you need the right tools and right acid. You can buy the tools and acid but with the price of gold way up, the price of the set would be very expensive now.

The set consists of a black very fine grained stone, like black Arkansas Novaculite, available through some Arkansas oilstone dealers...listed as Black Arkansas as the trade name. You want the opaque stone not the translucent.
Then you need a set of gold grading needles....the needles are 8, 10, 12, 14, 16, 18, 20, 22 Kt. Should be available through a Jeweler's Wholesale House or through select retailers to the jewelry trades...Check out a Jewelry Trade show to find these equipment sellers.

The object to be tested is rubbed against the black stone, "Touchstone" as it is known in the jewelry trades, to obtain a metallic streak. Then if the piece is marked, the appropriate needle is rubbed on the stone next to the 1st streak. Finally a drop of nitric acid is applied to both streaks. The acid eats the alloys away in short order, and what remains is gold.

A hand lens is then used, usually 10 X, to compare the color and distribution of the gold remaining with standard needle streak.

This test is somewhat objective but does prove that gold is present. Most jewelry stores and pawn shops that test this way, then give an offer based on a percentage of the total gold weight at 2Kt less than the supposed value. Experience has shown, particularly with unmarked jewelry, that this test may over estimate the gold content more often than underestimate it, and by doing so, the store owner is protecting his bottom line, which is the melt value of the gold should he send it in for scrap.

Hope you find this info of some interest. PS: The King does know his Gold!

[KingTotsalot]

Originally Posted by phantom

another note on troy weight. a troy pound of gold is 12 troy oz. not 16. it won't matter to most, but makes the difference of feast or famine to me.

yes phantom and a Troy Pound = 0.8228571 Advp. or English pound.

[KingTotsalot]

Originally Posted by Metal-Magnet

I've saw on pawn stars them scratching gold on some kind of pad and putting some type of liquid on it. Anyone know of this method?

The "scratch pad" you mention is a touchstone...usually black novaculite and the acid is nitric. The nitric acid removes the alloys and leaves the gold behind. The method is used to guestimate the K of the item...and is accurate to +/- 2 K....usually used to double check the marked K rating. Pawnshop owners usually make their offer based on 2 K less than the marking and the weight of the item...less about 30% so they can make a profit.

May seem crummy but they got to stay in business too and ain't ever gonna pay you full value cause they will just send it in the refinery if it does not sell in their shop for retail!

[ScubaDetector]

Gold plate has has a few different abbriviations

RG = rolled gold
HGE Heavy Gold Electroplate
Gold Overlay
GF Gold Filled

You will also find rings and bracelets marked real gold but they are not. BE suspicious of ANY double marks like 18K and 750. Most likely fake.

14kP means 14k plumb. That means TRUE 14k not 13.6 or whatever.

Siladium, Celestrium, SS Stainless Steel

ARG Copper, nickel and tin = junk

[Roger B]

Nice post Carol!