finishing.com logo
    HOME / sitemapFAQsBOOKSHelp WantedsAdvertiseContact   you are here: Hotline/Forum => Letter 31344
most fun in metal finishing

How do you tell the difference between gold and brass coins?

++++

Q. ASAP....PLEASE......I have a coin and I can't tell if it is gold or brass the only test I know to do on it is the magnet test. And the magnet doesn't stick to the coin. But that still doesn't tell me if it is brass or gold. I am a sort of collector, and this is driving me crazy, I don't have the means to go and buy anything to do the test. I thought I heard once that there was a test you can do with just regular household items to test for brass... PLEASE HELP!

MANY THANKS

CYNTHIA H deleted
HOBBYIST - DENVER, COLORADO, USA


A. There must be coin dealers and jewelers in Denver who can answer this question "by eye" almost before you cross the threshold of their shop, Cynthia, but who can test it instantly if need be.

The simplest test for you would be a weight test; gold is much heavier than brass, well over twice as heavy, 19.3 g/cm for gold vs. the vicinity of 8.5 g/cm for brass, depending on composition. Look up "Archimedes displacement experiment" if you don't quite understand. Good luck.

pic of Ted Mooney Teds signature
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey


++++

A. Try muriatic acidamazoninfo, if its a gold coin it will not be damaged, if its brass, well who cares...it wasn't gold anyway.

Bo Kønig
- Odense, Denmark


++++

A. For small metal objects specific density is very good test.

You need only precise balance.
1.weigh object in air
2.weigh object submerged in distilled water
3.Calculate density

(mass in air)X(density of liquid)
-------------------------------------
(mass in air)-(mass submerged in liquid)

4.Compare values: pure gold=18.88, gold 18K (light yellow)=15.4, gold 14 K (yellow)=13.6, brass(yellow)=8.40-8.55, water=1.00(20 C temp.)  

Good luck!

Goran Budija
- Zagreb , Croatia


++++

A. Density. Gold is much denser than brass.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK


++++

A. Open an old fashion car battery (unfortunately the new ones come sealed). Wrap a small piece of cotton or rag over a long wood or plastic stick, take out some "battery acid" and touch the coin. If no change in color or reaction, it is gold (or at least a very good and thick gold plate). Surest method remains the density check.

Guillermo Marrufo
Monterrey, NL, Mexico


++++

A. Take your coin to a pawn shop. They will know the difference.

Larry L deleted
equipment manager - Imperial Beach,CA USA


++++++

A. The simplest way employed by many jewelers is to rub the brass object between or with your fingers. Brass has a unique smell which will be transferred to your fingers and can be easily detected. Conversely, rubbing a gold object with your fingers produces no smell at all.

Dr. Alain G. Harvey
- Houston, Texas


++++++

thumbsup2Q. Grr, me too, brass or gold..... I shall also try to find out whether or not my £2 coin is brass or gold using the methods you have provided, thanks people :)

Brian R deleted
consumer - Cornwall, United Kingdom


++++++

A. Gold doesn't tarnish. Gold is much more dense than brass, but it has the same exact density as tungsten. Nitric acid dissolves almost every metal and alloy except for gold. One can also tell the difference in colour. Brass is pale and has a yellow tint to it. I hope this helps.

Cody Johnson
- Daniel, Colorado, U.S.


January 30, 2009

A. Rubbing it between your fingers is the best way to tell if it smells like any thing its not gold!

juuan sosa
- hayward California, usa


April 30, 2009

A. First wash the coin or small object you want to test with warm soapy water and dry very well. Very simply but carefully put the coin on the top middle part of your tongue and close your mouth, take a deep breath and taste it, if the coin has a funny taste it is not gold as gold will have no reaction with taste or smell in your mouth, other metals will, even brass but if you have any doubts to whether it is brass or some other metal you may not want to do this. Good luck, God Bless and don't swallow the coin :)

Doug Lang
- Havana, Illinois, USA


December 13, 2008

thumbsup2I bought a crystal ball paperweight with a gold colored cherub on top. I wanted to know whether it was brass or not. After reading many different tests, I decided on the "rubbing between your fingers" test. IT WORKED! My fingers had the most distinct smell after. Now I know it's brass! Thank you for the help in solving my problem.
Sincerely,

Tracy B.
- Las Vegas, Nevada, USA


+++++++

Q. I am trying to tell if a, (what appears to be brass) canopy bed is all brass. I did the magnet, it won't stick, & it does have a unique smell when rubbed on the inside of the pipe. It is very shiny on the outside & kind of dirty copper looking on the inside. I can't find any markings. I inherited this from my mom several years ago. Any help will be appreciated.

Dorothy Hurt
- Bakersfield, California, USA


July 16, 2009

Q. My father gave me some door knobs, I would like to know if they are brass or real gold. They are heavy, how can I find out which one it is

elizabeth shofner
student - raleigh, North Carolina usa


August 14, 2009

A. That one is easy, Elizabeth: they're not gold :-)

But if you want to check, there are already many good answers on this page, but check the density like Archimedes did --

Put the knob in a cup of water that was filled to the brim and capture the water that spills over and weigh it. Weigh the knob and divide by the weight of the water it displaced to determine its specific gravity. If the knob weighs 19.3x as much as the water, it's gold. If only 8.5x as much, it's probably brass. The difference is so great that there should be no ambiguity at all. Good luck.

Regards,

pic of Ted Mooney Teds signature
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey

May 28, 2011

A. The test is so simple that mass displacement is not necessary. To test gold from brass, even plated brass will show this is up, is to take an eye dropper of silver nitrate and of course the drop will change the area to pure silver. You know that old electron theory right? Silver nitrate will change gold to silver, but it is for earned a oneway trip. You cannot create gold with any molecular mix.

Anthony Nugey
- Rahway, New Jersey

December 2, 2011

Update on the Silver Nitrate, I recommend actually no more then one drop. The silver will wear away because it is the depth of Atomic in nature. I realize that it is not easy to get silver nitrate , check with your local jeweler and there is the importance, whether you want a coin to remain uncirculated, you cannot touch it. Also Gold does not tarnish like brass. Brass will dull to a greyish color and Gold will remain its yellow color. But the thought added here is that a brass coin has a specific tone when dropped on say a Formica surface as opposed to a gold coin will have a higher pitch. But alas if you're just selling it for its element, then you will find gold scratches and bends easier then brass.

Anthony Nugey
- Linden, New Jersey, USA


April 8, 2013

Hi Anthony. There are typos in your first response, but I'm not sure quite where. I think the thrust of it is that silver nitrate will not create a silvery deposit deposit on gold.

Regards,

pic of Ted Mooney Teds signature
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey

February 28, 2012

Q. I have this ring that I can't tell if its Gold or Brass, if I wear it, the inside turns dark but shiny on the outside.

James henry
- Nairobi, Kenya


March 9, 2012

Q. I have a large bell that is bronze and beautifully plated- with what appears to be gold. How can I tell if it's really gold, or is the plating brass? The bell is marked " Gorham + Co." 04-46.

Craig Loughery
Rotarian, Hobbyist - Ely, Minnesota, USA

April 2, 2013

Q. I have a brass ring with a coin on it, but want to know if the coin mounted on it is gold. How can I tell?

Louise Altu
- United Kingdom


June 8, 2014

Q. I found a chunk of metal on the coast when I was beach walking. It was green, covered in a green film that I had to scrape off with a knife. Thinking it was copper (because if turning green), I showed it to a guy who had a metal detector. He said it was reading like gold. Would gold turn green in seawater? The metal piece looks raw and unrefined, like it just came out of the ground. Somebody tell me what this could be? Thank you!

Joey mckormic
- puyallup, washington, america

ADD a Q or A to THIS thread START a NEW THREADView This Week's HOT TOPICS

disclaim

 seek

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & DevicesUsed & Surplus


©1995-2014 finishing.com     -    Privacy    -    Search