Home /
Search 🔍
the Site
pub Where the world gathers for
plating, anodizing, & finishing Q&As since 1989

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!


CYNTHIA H [last name deleted for privacy by Editor]

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.

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Try Muriatic Acid [affil link], 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
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 [last name deleted for privacy by Editor]
equipment manager - Imperial Beach, California 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

thumbs up sign Get something you know is gold and rub it with your fingers aggressively. Then smell the surface of what you were rubbing. Then do the same with your coin. Brass has a smell to it and it smells metallic.

Poe Flippo
- Raleigh NC
October 29, 2022

thumbs up signGrr, 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 [last name deleted for privacy by Editor]
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.

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
January 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

thumbs up signI 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.

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

A. Hi Dorothy. Sounds like brass to me :-)

If it's not steel/iron as demonstrated with a magnet, the only other thing it would likely be is aluminum -- and aluminum should be very light, and would be unlikely to look like dirty copper on the inside.


Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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
July 16, 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.


Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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
May 28, 2011

A. Update on the Silver Nitrate, I recommend actually no more than 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 [returning]
- Linden, New Jersey, USA
December 2, 2011

thumbs up sign 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.


Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

April 8, 2013

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
February 28, 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
March 9, 2012

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
April 2, 2013

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
June 8, 2014


Q. I found this round, amulet, coin whatever you want to call it. Lol. I read all your posts about knowing if it's brass or gold. The front has an American flag on left and China flag on right. Between the flag is an eagle on top of the world. It says on top of coin" United States Marine Corp". At the bottom it says "Semper Fidelis" the back has some type of dragon with words "Marine security guard detachment" at the top. The bottom says"Chengdu,China".

Jennifer Marth
- Easton, Pennsylvania, usa
April 7, 2016

A. Hi Jennifer. Please google "Marine security guard detachment" and you will understand what this is. You didn't exactly ask a question, and you say you've read the suggestions for telling brass from gold, so I'm not positive what you want from us at this point except this answer: it's not gold :-)

Although it has no value to anyone else, it probably has strong sentimental meaning to someone who served our country in Chengdu, so I'd urge you to put a note on the bulletin boards of stores or meeting places near where you found it.


pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey


Q. I recently found a round disc at a thrift store. After posting a pic on FB I found that it is an Astrolabe. No tarnish but a light film that I rubbed off with a tissue for a nice shine. It has a slender flat bar transversing the front that has some flaking. Looks like rust underneath. It appears to have a good bit of value so I'm afraid to add chemicals in case the plating is pitted or will flake more. Arm is magnetic and disc slightly. Thinking maybe pot metal core? Since it had not a real tarnish and shined up easily, I am hoping for gold plate & not brass. Any thoughts?

Glen whitaker
- Port Charlotte, Florida USA
February 26, 2017

Q. Hi all

I have an alloy I picked up like nuggets. I gave a friend of mine to go test for me. He came back saying its 75.6 copper, 21.7 zinc, 2.4 silver and 0.2 iron. When I picked them I thought they were gold. When polished they shine like gold and become very smooth and almost slippery. Could my friend be wrong? They don't react to anything. What kind of brass is that? Is it of any value? They pass all the gold tests. Still have not found nitric acid but other acids don't do anything to them. Am confused now.

graphic design - Johannesburg South Africa
June 25, 2019

But a really easy way to know that something isn't gold is the Archimedes weight test. Weigh the nuggets, then put them into a glass of water filled to the brim placed inside a dish that will catch the spillover. Divide the weight of the nuggets by the weight of the spillover and you have the density of the nuggets. As noted earlier on this page where we appended your inquiry, gold is about 19.3 times as heavy as water and brass is only about 8.5 times as heavy as water.

There are other heavy things which this test doesn't rule out, but the difference between brass and gold will be dramatic. Good luck.


pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. The best answer is take a pencil torch or house hold torch to it and if it discolors it's brass get it glowing red if it melts it's gold if it turns colors it's brass as the question stated home test ,not buying anything and easy those things considered I feel that would be the best answer however if it's a valuable coin you don't want to melt or warp it but the test could be done with care not to do either.

Carl Fuller jr
Electronic repair - Kuna Idaho

January 27, 2020


Hi Alderton
Your friend's analysis indicates that what you have is one of the many types of brazing alloy. My guess is that your 'nuggets' were picked up from under a badly made joint where they dripped onto the floor.

Just out of interest I tried the suggested test. I shone my household maglite pencil torch onto a gold ring... I am still waiting for it to get hot.

geoff smith
Geoff Smith
Hampshire, England

A. The least invasive way to identify if it is Gold or Brass is to detect their standard electrode potential with a volt meter.

Metals: Unknown brass/gold piece, copper example (electric wire grade), electrolyte: salt Water or magnesium sulfate (Epsom Salt, about 10 grams per 100 ml), a sheet of absorbing paper towel, soak the towel in the electrolyte, put both metal next to each other(they should not touch each other or make contact) if Copper metal is cathodic to the sample metal then the unknown metal is brass, but if Copper is anodic to the sample metal then the unknown metal is gold (even 10 Karat gold is more noble than copper)

Galvanic Cell: Anode(-) vs Cathode(+)

Marvin Sevilla
- Managua, Nicaragua

finishing.com is made possible by ...
this text gets replaced with bannerText
spacer gets replaced with bannerImages

(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

Chemicals &
Consult'g, Train'g
& Software

About/Contact    -    Privacy Policy    -    ©1995-2023 finishing.com, Pine Beach, New Jersey, USA