Gold is a relatively soft metal, and consequently gold coins that are made of pure gold or a high percentage of gold, can be relatively soft and malleable. Therefore, biting the coin would leave a mark or an indent if it was real gold.
If it's real gold, your teeth will form small dents in the metal. Fake gold won't dent at all on a bite test! Now, before you chip a tooth, remember that gold is a soft metal so there's no need to bite down very hard.
Real gold is softer than human teeth and, therefore, would be left with a mark if bitten, according to CNN.
It's possible to leave teeth marks in objects containing pure gold, silver, or copper because they are all soft metals. The biting method was utilized to verify if gold coins and other gold objects were genuine or forgeries.
In their pure forms, gold and silver happen to be very soft metals—soft enough that you should be able to mark them with your teeth. According to the Mohs hardness scale—which relates pairs of materials according to which one will scratch the other first—gold scores a 2.5 and silver, which is harder, a 2.7.
Biting metal is a tradition
During the California gold rush in the late 1800s, people would bite into gold to test if it was real. The theory was that pure gold is a soft, malleable metal. If a bite left indentation marks on the metal, it was most likely real. If it wasn't, you could break a tooth.
Many people are curious to know why in the old days it was common to bite gold coins – or other kinds of items made of gold – to confirm whether or not they were real. This practical and crude method was used for the authentication of gold since this metal is very malleable.
Gold is a heavy metal, so heavy that it will sink in water. If you drop your jewelry in a glass of water, real gold will drop straight down. Remember that 18- karat gold is 75% gold mixed with other alloys.
An average full “gold” crown might weigh between two to three grams. For our calculation we will assume a spot gold price of $1000 per ounce. If the crown's alloy is 10 karat (40% gold), its value might be as much as $40.
Pirates biting gold
The rationale for biting a coin was the supposed widespread dissemination of gold plated lead coins in the 19th century. Since lead is much softer than gold, biting the coins is a sensible test for counterfeiting.
As the earth's crust is estimated to mass around 2.6 * 1022 kg, it means that there is around 400 billion kg of gold throughout the entire crust. Much of it will never really be accessible, of course, but there really is quite a bit out there.
Pure gold is very malleable, and is not ideal for use in the mouth, where the forces of chewing may deform the metal. For this reason, pure (24k) gold is not used for dental crowns or other dental work.
Gold is a particularly non-reactive element and is not absorbed during the digestion process, so it is safe to eat.
How to Test If Gold Is Real with a Lighter. The first test is also the easiest test: try to burn your gold. If it's real gold, it will get brighter as you apply the flame but it won't actually catch fire and burn. If your gold piece starts to smoke or gets darker, you likely have imitation gold.
Although it is very strong, gold is the most malleable of all metals. Pure gold is too soft to withstand the stresses of everyday wear, so it is combined with different alloys to give it strength and durability. These alloys include metals like silver, copper, nickel, and zinc.
What to do: Hold the magnet up to the gold. If it's real gold it will not stick to the magnet. (Fun fact: Real gold is not magnetic.) Fake gold, on the other hand, will stick to the magnet.
10-Karat Gold
10k gold is the lowest solid gold alloy used for jewelry. It's composed of 41.7% gold and 58.3% alloy. Appearance: 10k gold is pale yellow in color. It's the least yellow of all the karat types since it contains the least amount of gold.
Drop the Item in Water
Real gold is a heavy metal and will not float, so if your gold item floats you know it is not real gold. Also, if you notice rust or tarnishing on the item after being in water, this is also a sign it is not real gold since gold doesn't rust or tarnish.
Each Australian Gold Coin is struck in 99.99% pure gold and individually packaged in hard plastic capsules at the Perth Mint.
The one ounce coin, $50 face value, is 1.287 inches (32.70 mm) in diameter, contains one gold troy ounce and weighs 1.0909 troy ounces (33.931 g). The one-half ounce coin, $25 face value, is 1.063 inches (27.00 mm) in diameter, contains 0.5000 gold troy ounce and weighs 0.5455 troy ounce (16.966 g).
It's priceless, of course, but it also happens to be worth at least $750 at current metal prices. IOC regulations are generally understood to require that Olympics gold medals contain at least 92.5% silver, plated with at least 6 grams of gold.
Here too, gold is considered an amulet, thought to provide protection against evil, danger and disease. Especially in Northern and Western India, where the practice of placing gold in the mouth of the deceased is widespread, gold is considered to have a strong protective influence.
According to the International Olympic Committee, gold medals are required to be at least 92.5 percent silver, and are plated with about 6 grams of pure gold. A spokesman from the Beijing 2022 committee confirmed that this year's gold medal follows those regulations.