Gently drop your gold object into the water. Real gold is a heavy metal and won't float, so if your gold item floats, you'll know it's not real gold. In addition, if you notice rust or tarnish on the item after being in the water, this is also a sign that it is not real gold, as the gold will not rust or tarnish. The most reliable method to check if something is gold or solid gold plated is to take an acid test.
For the acidity test, take a small piece of jewelry or, with a small needle, scratch a small part of your gold, take a dropper found in the acid kit and fill it with acid. Now use this dropper to inject that scratch with a small drop of acid. The striped part is likely to change color in response to reaction with the acid. Carefully observe what color you have changed to and match it with the color chart provided in the acid kit.
Not only will this tell you if the gold was fake or real, but it will also help you identify the real metal it is. To test your gold at home with this method, you'll need to get an acid test kit that is readily available at jewelry stores and even online. The acid test is also used to determine the carats of gold. If you decide to use this method, read the instructions in the kit carefully before starting the procedure.
One of the most foolproof methods to test your gold jewelry is the ceramic scratch test. For this method, get an unglazed ceramic plate or piece of tile and scrape a piece of gold across the surface. Real gold isn't magnetic, but many other metals are. If you have a relatively strong magnet (somewhat stronger than a fridge magnet), you can easily check if your gold is real by placing the magnet close to the piece and seeing if it is attracted by the magnet.
Then, for each needle, repeat the gold line parallel to yours and write the carat symbol above the line to know which acid is for which mark. When you get a gold item, it doesn't need to be in its purest form, jewelers often mix other metals into gold to make it more durable. You should proceed to test with gold testing machines or, if you have pure nitric and hydrochloric acid, perform the aqua regia acid test to detect gold in your scratch sample. The most accurate gold testing machines use X-ray fluorescence (XRF) spectrometers, but they can cost thousands of dollars.
It may not be real gold, but it's still something some people collect, such as black ruthenium gold-plated coins. Comparing the reactions of the test needles with the reactions of your object will allow you to identify the purity of the gold. Next, place your black gold test stone on the glass and take your gold object and carefully scrape the gold off the stone until it leaves a slight line. After placing the gold piece on the right sensor, you should select the gold sample that you expect it to be.
A piece of 18-carat white gold can have a density of between 14.7 and 16.9 grams per milliliter. It has even found its way into everyday language, with expressions such as heart of gold, gold standard and good as gold. The terms “gold hallmarks” or “gold marks” refer to a set of mandatory marks that are engraved on the gold item. Real pure gold, when exposed to flame, becomes brighter after a while as it heats up, but does not darken.
Jewelry producers often mark their pieces with stamps, which are called symbols of gold jewelry marks. With a lot of fake gold pieces circulating around the market, you can't always take your gold jewelry at face value. The Hallmark test is not 100% accurate on its own because it doesn't provide any reliable evidence that you have real gold coins, bars, or jewelry. Below are two overviews of the most recommended gold analyzers: the Sigma Metalytics precious metal tester and the Thermo Scientific XRF analyzer.