How to test gold products with iodine

Testing gold with iodine is a fairly well-known method of testing gold items for originality and authenticity. But as a result of the use of this technique, the question often arises of how to purify gold from iodine. Despite the need for cleaning, the popular technique does not disappoint. After all, the increasing number of cases of deceptive quality of gold products being offered is worrying buyers more and more often. Even Archimedes, who lived before our era, more than once tried to solve the problem of testing the gold on his crown to find out whether it was genuine. This task remains significant today. With the use of modern technology, precious gold metal is becoming not so difficult to counterfeit. Meanwhile, the price of gold products is rising. Therefore, when you buy gold jewelry, you want to be sure that it is not a fake. At home, it is impossible to verify the authenticity of the metal one hundred percent, but there are simple checks that will reduce the possibility of a case where gold jewelry may be fake.

Instructions

Probably everyone has such a drug as iodine at home. If not, then it can easily be purchased at a pharmacy, since it does not require a doctor's prescription and is cheap. In medicine, iodine is considered an antiseptic. However, it is also used for other purposes. For example, a widely known method for testing gold is iodine, where it is used as an indicator to determine the authenticity of the metal. However, the drug will only help in recognizing gold. For other metal products it will not show the true result. So, having decided to try this method, you need to do the following.

1. They take gold jewelry. Usually, doubts arise in samples 583 and 585, since their tint may be slightly reddish, which can raise doubts. But it may also be associated with the presence of an alloy in the metal composition.
2. Then the product is lightly sanded on the inside. This is necessary for the reaction with iodine to occur. Most often, sandpaper is used for this, although you can use another abrasive.
3. After soaking a cotton swab in iodine, apply it to the gold item in the place of wear. It doesn’t matter whether a small or large amount of iodine will participate in the reaction. Therefore, you need to try to apply only a small, unnoticeable spot. The reaction will not increase depending on the size of the abrasion area, but then you will have to spend more effort to wash it, and a trace of abrasion may remain.
4. It remains to monitor the reaction. If a dark color stain appears, then the jewelry is genuine. It is precisely made of precious metal. But if the color remains the same, then the product is not gold, but bronze, copper or brass. The chemical reaction occurs because gold is able to react with halogens. And iodine is exactly that.

Don't try it on your teeth!

Gold is a soft metal, so if you squeeze it hard with your teeth, marks will appear. Agree, the seller will not like it and will force you to buy.

Athletes test their medals for the sake of photos. Moreover, gold medals are actually just gold plated.

By the way, fake aluminum behaves exactly the same way, so if the seller insists on a “teeth test”, don’t be fooled.

On the other hand, only a new product does not have even small scratches on the surface. If a person claims to be selling his used gold, but it appears to have only come from a factory, something is wrong here.

other methods

To check, you can use not only iodine, but also other substances, such as lapis pencil, vinegar, magnet. Your own hearing will also help. Many people know these methods. Therefore, if there is no iodine in the house, then it is quite possible to use them as an alternative method.

The lapis pencil contains silver nitrate, which is the active ingredient. The product is used in medicine for the purpose of cauterization. With its help, a test is done, the opposite of iodine. Gold is the only metal that will not react with a pencil. All others will change their color. However, if the product is of low quality, then the result is in question.

All you need to do is leave the decoration in the vinegar for only half a minute, during which you observe the reaction. There will be no reaction to gold. But other metals will begin to oxidize. But, if the sample turns out to be less than 750, then it is also difficult to judge the reliability, as in the previous case.

Attraction with a magnet will reveal the presence of a high iron content in the jewelry. Gold will not react to a magnet. However, at the same time, metals such as aluminum and copper are also not magnetic. Therefore, the experiment will only show the presence or absence of iron.

If a person has a good ear for music, he will be able to distinguish gold, since it is a sonorous metal. To do this, it should be thrown onto a smooth surface. Vibration should be heard, like crystal. Other metals, when hitting the surface, emit a heavy sound that is somewhat harsh on the ear. But, of course, this method cannot be called simple for the average person.

Attach a magnet

Plating steel or other alloys with a high iron content with gold or its imitation is a common practice. Only ferromagnets are strongly magnetic - iron, cobalt, nickel, gadolinium, terbium, dysprosium, holmium, erbium, thulium.

Dimagnets (for example, water or table salt) and paramagnets (aluminum, etc.) are weakly magnetic. All non-ferrous metal is not magnetic.

If it happens on the beach or in places where tourists gather, buy the cheapest magnet in a souvenir shop and attach it to the product. If it sticks, it’s definitely a fake or the metal is of too low standard (too many iron impurities). If not, perform other checks.

Method of purification from iodine

Having completed the iodine test, another question may then arise on how to get rid of a stain on a gold item. After all, iodine, as we found out, leaves dark spots. However, you should not worry about this, since in this case special work will not be required. But you can be sure that the jewelry is actually gold.

Over time, the stain will disappear on its own. But if it is important to erase it urgently, then you can use one of the following cleaning methods after checking the gold. Solutions using soap or powder will be useless in this case, since the substance is resistant to them. The following will help.

1. Hyposulfite can act as a cleaner. It is used to develop photos in the old way. Prepare the liquid as follows: take one tbsp. a spoonful of fixative and dilute it in a glass of water at room temperature. The gold item is kept in this solution for thirty minutes, and then washed under waste water and dried.
2. Ammonia will also help. But before using it, it is worth considering that it will not always have the desired effect. In addition, the smell will take a long time to dissipate, within 3 days.
3. You can also use the oldest method, which was known to our grandparents. To do this, take 70 g of soda, 80 g of lime and 20 g of salt. All components are mixed and dissolved in one liter of water, where the gold product is then placed for an hour and a half.

It is also worth remembering that testing gold for authenticity using iodine is only suitable when it is made of solid metal. If the product is gold-plated, the method will also indicate authenticity only if the corresponding layer is not erased. In addition, this can ruin the decoration. Therefore, it is better not to risk it and take it to the master.

Cleaning can be done at a jeweler as well as inspection. Naturally, they do all this at home for free. However, the result may be unreliable, and during the procedures there is a risk of damage to the jewelry. On the other hand, by contacting a jeweler, you can not only confirm the authenticity of the product, but also find out the sample of the existing alloy. A specialist will determine a reliable result in just a few minutes. Once upon a time, this required making cuts or cuts on the inside. However, today the inspection is carried out without compromising the integrity of the jewelry. The method consists in determining the density of gold and chemical. reactions. After checking, a specialist receives a document containing information about whether the jewelry contains gold or not.

Water test, Archimedes method

For the test you need: high-precision scales, thread, measuring cup, water (distilled will give a more accurate result), a table of the density of materials.

Density of precious metals:

To make gold jewelry, an alloy of gold and other metals is used. To indicate the percentage of gold, jewelry is marked with a hallmark. The higher the standard, the more expensive the jewelry. Also, the higher the percentage of gold content, the higher the density of the entire product.

Archimedes' method is based on these features. How to take measurements:

1. Weigh the product (m).
2. Find the volume - put a glass of water on the scale, reset the weight (the scale should read 0). We lower the product being tested into the water on a rope (without touching the walls and bottom), and record the readings (v).
3. Carry out the calculation using the formula - p = m / v.
4. The resulting density (p) is compared with the table (density of precious metals).

For clarity, check out the video on density measurement:

How to check authenticity in a store

People do not always have the opportunity to use home testing methods or take it to a jeweler. For example, you need to know exactly how to identify gold when purchasing it in a store. If a product is purchased on the territory of Russia, then it must have a sample and the letter of the person who puts the stamp on it. If this is not the case, then there is no need to talk about legal gold. Most likely it's costume jewelry. The quality of gold jewelry varies from country to country. Therefore, when it is bought in other countries, in addition to the sample, you must pay attention to other characteristics.

1. The polish should be shiny.
2. The coating and spraying are done evenly, and the color is the same.
3. If the product contains a stone, it is firmly inserted.
4. All units have their own tag made of white thick paper, in which there is a hole with a stretched thread. Here you can find information about the product: its weight, sample, manufacturer, name, legal address.

The presence of impurities can be determined visually by the color of the product. White color is formed with the help of silver and platinum, yellow - with silver and copper, red indicates that copper predominates in the alloy, green is obtained by combining silver, copper and cadmium, and a gray tint is acquired with the presence of steel. It is not recommended to purchase such a product over the Internet, as in this case there is a high risk of counterfeiting.

Testing gold in contact with other gold jewelry

Every family will definitely find gold jewelry that has a good reputation and is definitely made of gold. It was either inherited or has great value and importance. Using this script you can easily check other gold items.

To make the experiment cleaner, it will be better if both decorations have the same sample. With these gold jewelry, you need to draw two lines on a hard object, such as a stone with a smooth surface, with equal force. The marks should be uniform. The line prints must completely match or at least be similar.

Safety precautions when working with chemicals

Chemical reagents are quite aggressive substances, so when working with them you must adhere to certain safety rules. This is especially true for the use of acids.

You need to lay a thick fabric on the surface where the testing procedure will take place. Hands are protected with gloves, clothing with an apron. Acids are diluted in a special container, added in a thin stream to distilled water. The liquid may become hot. Before using the composition on gold, it must be cooled.

conclusions

If you buy gold secondhand or from an unverified store, use as many methods as possible to ensure the authenticity of the product. The main thing is not to try too hard, so as not to spoil the soft metal.

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