2006-06-14 05:46:46 · 13 answers · asked by still learning 2 in Science & Mathematics ➔ Chemistry
The same way that Archimedes did -- determine the density.
Measure the mass of the coin, then determine its volume by water displacement.
Density = mass/volume
The density of pure (24 karat) gold is 19.3 grams/cm3
For other alloys and karat ratings of gold, check this table:
http://www.24carat.co.uk/densityofgoldandothermetalsframe.html
Most U.S. gold coins in current production are 22 karat gold.
You may need to do some more research to determine the expected gold content of your coin, and then you can compare it to the chart for a density value.
2006-06-15 08:45:24 · answer #1 · answered by Dave_Stark 7 · 3⤊ 0⤋
Ok. First of all, weigh the coin, preferably with an electronic balance. Then get its volume. You could do this by filling a glass with water right to the brim until the water is just about to overflow. Slowly and carefully place the coin into the water and have a container underneath the glass to catch the water that spills over. The coin will displace its own volume of water. You could then pour the water that has overflowed into a graduated container to get a measurement of the coin's volume. If this sounds too much like hard work, take diameter(d) and width(w) measurements using a ruler. Get the surface area of the face of one side of the coin by Pi*d*d/4. Then multiply this value by the width or thickness of the coin. This gives you a volume of the coin but it's not as accurate as the water displacement method because the two faces of the coin are probably not perfectly smooth ie. there are rises and falls of some design. So when you've done all this, divide the weight of the coin by its volume. Gold is 19.3 times the density of water so if you get a figure in the region of this, it's gold.
2006-06-14 09:04:13 · answer #2 · answered by mmlxxviii 2 · 0⤊ 0⤋
This Site Might Help You.
RE:
how can i tell if my gold coin is really gold without taking it to a jewellers?
2015-08-10 05:28:48 · answer #3 · answered by Horacio 1 · 0⤊ 0⤋
If it's solid gold, you should be able to scratch it with a fingernail (which is why in all the old movies you always see people biting the coins)... gold is a much softer metal than most and will bend/scratch very easily
2006-06-14 05:52:01 · answer #4 · answered by D0gmeat 3 · 0⤊ 0⤋
gold coin gold jewellers
2016-01-29 21:20:57 · answer #5 · answered by ? 4 · 0⤊ 0⤋
ok gold is valubl because it is so unreative now it you dont value this gold coin you could sumit it to some chemitstry test but after you compleat the test you probly would not have a coin so.
any way most imitatinon gold metal have iron in them but the coin in a oxygen rich inviroment and keep a little water on it if its iron it should rust in a cople of days
2006-06-14 07:13:52 · answer #6 · answered by lone 2 · 0⤊ 1⤋
Open up your car battery, pour out some of that sulfuric acid (be careful), and then drop your jewel in there. If it's not gold, it'll change color, start bubble, and finally dissolve. Gold will not sustain any damage.
2006-06-14 07:40:07 · answer #7 · answered by Anonymous · 0⤊ 0⤋
First of all, DO NOT CLEAN IT. It Ruins the value.
If you have a scanner, scan it and post a picture.
Otherwise, take a look at this website:
www.pcgs.com
or:
www.coinfacts.com
Find your coin there and compare the pictures
2006-06-14 05:50:08 · answer #8 · answered by Ozymandias 5 · 0⤊ 0⤋
WEigh it. Then compare the weight of yours to the known weight of that type of coin. I.e. a Kruger is one ounce. It would be vrty dificult for a forger to match the exact weight with other metals.
2016-03-17 22:19:31 · answer #9 · answered by Maria 4 · 0⤊ 0⤋
Take the coin, and hold it in your teeth, if it soar it is grape, if it is sweat it is peppermint, if non of both it is gold indeed
2006-06-14 07:33:44 · answer #10 · answered by Okay 1 · 0⤊ 0⤋