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.
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.
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.
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.
During the 1800s gold rush in California, the practice of biting gold to discover if it was real or fake began. Real gold is a soft material, so bite marks would appear on the gold and could easily be fixed. If the gold was fake, it would hurt your tooth to bite down on it.
Place your jewelry on a table or hold it in your hand, pour some white vinegar on the metal directly (a dropper can also be used) if the metal of the jewelry changes its color, it is not pure gold and if it keeps shining then you have real gold in your hand.
Gold is a very soft metal, so scratching it with a hard object like ceramic will leave a golden or a yellowish streak. On the other hand, fake gold is often made of metals that are darker in color, so you'll see a dark streak instead.
Any precious metal is going to show scratches, regardless of whether it is palladium, platinum or gold. None of these metals is scratch resistant.
A rectangular shape with the corners shaved off will tell you immediately that the item is gold. An oval stamp would indicate the item is silver. A 'house' shaped mark is used for platinum items.
The most common reason for skin discoloring when wearing gold jewelry is metallic abrasion. Metallic abrasion is a result of makeup on skin or clothing. Cosmetics often contain compounds harder than jewelry, which wear or rub off very tiny particles.
Acid test.
An acid test can reveal the karat of solid gold jewelry, but it can also show whether jewelry is solid gold or gold-plated. With an acid test, a small sample of the jewelry is removed and exposed to acid to induce a color change. The resulting colors indicate which type of metal the jewelry is made of.
Do gold braces make your teeth look yellow? Because of its tint, Gold braces give off a yellowish appearance that can make some peoples teeth appear more yellow than they actually are. However, if you suffer from a nickle allergy and are in need of metal braces, they may be your only other option.
Being purely metal, gold crowns have the potential to last for 20 years or more.
In a nitric acid test, a jeweler places a few drops of the acid on the piece and watches the reaction. With copper, the reaction usually causes the liquid to turn green, give off fumes, and sometimes bubble. This response is known as a hard cupric reaction and indicates that your piece is not real gold.
In addition, actual gold will leave a golden yellow streak when scraped on a piece of unglazed porcelain. Pyrite and chalcopyrite will leave a dark green to black streak and the common micas will leave a white streak.
Only polishing will remove scratches from gold and platinum. However, the patina of fine scratches that develops over time can add beauty to the jewelry and can reflect the journey a piece has taken. The polishing process removes metal and is only recommended to be carried out a few times over the life of the piece.
If the gold is real, it will shine. If the gold is fake, it will change color.
Gold alloys will still receive scratches and dents over time, but these can be easily polished out at home with a polishing cloth or by a professional jeweler with special tools.
If your gold piece turns black or green when the vinegar is on it, or if it starts to smoke or fizzle at all when the vinegar touches it, it is most likely not real gold. If your gold piece does not change colors and does not fizzle or react to the vinegar in any way, it is probably real.
Scratch Test
For this method, get an unglazed ceramic plate or piece of tiles and scrape a piece of gold across the surface. Real gold will leave a gold-colored marking, which other metals will just leave a black streak. Be careful to only scrape the tile enough to reveal a gold marking to avoid damaging your jewelry.