How much gold content can be in magnetic jewelery?

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goldanalog

Active member
Joined
Aug 11, 2020
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35
So, just a general question based on your experience. I realize 10K has to have a lot more metals in it.

Most people run when they see some form of magnetism in jewelry but my instinct tells me from a refiners point of view that's not always wise.

Also, if the jewelry is non-magnetic and doesn't has high gold content, what's the best way to test for silver when its gold tone?
 
The ferromagnetic metals do not make good jewelry and can give undesirable properties in jewelry made of karated gold.

The ferromagnetic metals like iron, nickel, cobalt, and steels (made of iron), we also have some rare-earth metals which are attracted by a magnet such as gadolinium, samarium, and neodymium.

Gold, copper, and silver are not attracted to a magnet and are the main metals used in karat gold jewelry.

So the magnet is a good test for karat jewelry, if it is magnetic it is not karated gold but could be plated or fake...

Cheap jewelry (not karat gold jewelry) can be made with just about any metal, including magnetic and, or nonmagnetic metals and can be plated with gold, or gold-filled (these normally contain a lot less gold or very little value in recoverable metals)...

Testing for silver, Schwerters solution gives blood red, in a deep scratch, a drop of nitric can reveal base metals like copper when followed by a drop of HCl silver gives a white precipitate...

C.M. Hoke's, She has a good book on testing for gold and other metals, Pawnbroker Bob also posted his very informative book on testing these valuable metals, you should be able to find both of these books with a forum search.
 
Thanks for your answer.

Any experience with the material that is barely magnetic? Would that have a mix of ferromagnetic and non-ferromagnetic metals? I'm wondering if there is certain reasoning in the mind of the jewelry manufacturer when to use silver verses copper.

It's interesting that as some people say "Gold was once cheap" in that for a time gold was at a low price. I often electronically test non-marked materials as having gold content above the "flash gold" reading. Items marked Avon and Monet will often have >10K readings. I'm wondering maybe some of this stuff was made at a time when marking gold was not such a big deal.
 
Nick being a jeweler can give a better answer than I can, and give more details on the alloying of karat gold.

Some Karat gold like 18k can contain iron in a very small quantity to give color but the karat gold alloy is not attracted to the magnet.

Silver is used in changing the color of the gold alloy, copper, and silver besides coloring also makes the gold harder less likely to wear away as fast and hold its shape better.

You need to work on acquiring better testing methods, the electronic tester may give you some clues, but when it comes to buying gold it is not the tool I would carry in a toolbox, to me in my mind using the electronic testing device to test for gold, would be like using a metal detector it may give me clues but it is not what I would rely on to verify gold or its value...

I would trust a file and a drop of nitric acid overusing some electronic gold detector any day of the week when buying gold.

Search for Hoke's testing precious metals and pawnbroker Bobs book on testing precious metals, add them to your tool box.
 
Number one rule to remember is gold was never cheap.
Alloys for gold karat items have copper silver and zinc as a basic alloy, some miss the silver and add more zinc.
Filing and acid testing will answer most of your questions very quickly, slightly magnetic items may have springs such as catches on chains and bracelets or use steel to strengthen bangles, there is a lot to learn if you buy scrap jewellery as many things can skew the returns.
 
I'm finding a lot of non-marked, non-magnetic silver colored items. I haven't got to testing any yet with acid. Any way of sorting out which isn't even worth testing? I know the polish test: if it polishes up like silver from a tarnished state, it is at least silver plated. Some of it is quite shiny, and realize silver can be treated with palladium with so it does not tarnish.
 
Not completely on spot with the OP, but remember that pure gold and silver (along with other metals) will react to a sudden magnetic field. The gold or silver (not in powder form) will jump when you suddenly put a neodymium magnet up to it. Somewhat fascinating.
 
geedigity said:
Not completely on spot with the OP, but remember that pure gold and silver (along with other metals) will react to a sudden magnetic field. The gold or silver (not in powder form) will jump when you suddenly put a neodymium magnet up to it. Somewhat fascinating.

That is from induced current, eddy currents. Any metal or conductor will react in that way, how strong it will react only depends on the resistance of the material coupled to the density. So aluminium reacts very strong to that test.

One of the most impressive ways to show that effect is to have an aluminium tube and drop a strong magnet through it.

Göran
 
g_axelsson said:
geedigity said:
Not completely on spot with the OP, but remember that pure gold and silver (along with other metals) will react to a sudden magnetic field. The gold or silver (not in powder form) will jump when you suddenly put a neodymium magnet up to it. Somewhat fascinating.

That is from induced current, eddy currents. Any metal or conductor will react in that way, how strong it will react only depends on the resistance of the material coupled to the density. So aluminium reacts very strong to that test.

One of the most impressive ways to show that effect is to have an aluminium tube and drop a strong magnet through it.

Göran

Just tried it although I used an aluminum channel (rectangular) and the magnet slowly dropped through it. Very cool!!
 
It's a cool effect, especially if you look inside the tube and see that there isn't anything holding it back. People can get quite confounded by it if you just show it to them without an explanation. :D

Easy test to separate glass platters from aluminium ones when scrapping disks without creating shards. Put the platter on a table and sweep fast over it with a strong magnet. The aluminium one will be dragged along a bit while the glass one lies still.

Göran
 
I'm wondering what the next step is to do with my "flash gold" collection. To repeat from a previous post: I have an electronic gold tester, an RS Mizar ET18. It has five readings: Non-gold, flash gold, >10K >14K and >18K. Flash gold is the supposedly thinest gold plate. Knowing how valuable even a little amount of gold is, and that you guys said you wouldn't trust an electronic tester, are there ways to know which is better to do acid testing on? I have a fair amount of it.

Can you trust flash gold readings on electronic testers? That is, could they give a false reading of a good amount of gold present?

Thoughts:

1 Heavier weight per item's water displacement -- but what other metals could be in there that are heavy?

2 The obvious signs of higher quality jewelry (non-magnetism,etc.).

I'm wondering if anyone has any ideas I haven't thought of. I would rather have someone wear the jewelry without an ugly scratch mark if possible.
 
Why does Google say this:

List of Magnetic Metals
  • Iron. Iron is an extremely well-known ferromagnetic metal. ...
  • Nickel. Nickel is another popular magnetic metal with ferromagnetic properties. ...
  • Cobalt. Cobalt is an important ferromagnetic metal. ...
  • Steel. ...
  • Stainless Steel. ...
  • Rare Earth Metals. ...
  • Aluminium. ...
  • Gold.
 
Not all metals are strongly or weakly attracted to a magnetic field.

Some can seem to repel, or become attractive, with an induced magnetic field from a magnetic field moving across the metal), a magnetic or induction of forces in the metal opposes the magnetic field of a moving magnet.

A magnet field moving by a coil of copper we move electrons inducing current in the coil of wire, or moving electrons through a coil of copper makes a magnetic field around the coil of wire which can attract or oppose a magnetic field (like the eddy current principles).

https://en.wikipedia.org/wiki/Magnetism#Ferromagnetism
Different metals can react differently to a magnetic field

https://en.wikipedia.org/wiki/Ferromagnetismhttps://en.wikipedia.org/wiki/Diamagnetismhttps://en.wikipedia.org/wiki/Antiferromagnetismhttps://en.wikipedia.org/wiki/Paramagnetism
Metals like iron can loose its properties of magnetic attraction at high temperatures (curry).
 
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