When your 22 karat gold jewelry tarnishes, it does not mean that it is not real gold; it only means that your gold jewelry is not 'pure' gold or 24 karat gold. Any thing which is below 24 karat gold can tarnish or discolor under certain circumstances which we will discuss here. The information available online is very confusing, so for our readers benefit, we have written this blog to provide authentic information on how real gold can tarnish, become black or discolor and have also included tips and preventive measures.
24K gold is also called pure gold or 100 percent gold. This means that all 24 parts in the gold are all pure gold without traces of any other metals. It is known to be 999.999 per cent pure. Only pure or 24K gold stays shiny, and it does not rust, discolor or tarnish as pure gold is the least reactive chemical element. But pure gold or 24 karat gold is too soft to be used in jewelry so it is usually alloyed with other base metals. 24K gold is mostly used to make coins, bars and is also used in electronics and medical devices. Usually the highest purity of gold in which ornaments can be made is 22K because 24K gold is too soft to make ornaments. (Suggested Read: What does gold purity mean? )
All other gold purities like 22K gold or 18K gold are usually alloyed with other metals such as silver, copper, zinc, and nickel to make gold jewelry because the alloys increase the hardness of the metal and helps the metal gain a higher polish and brighter luster. It is these other base metals alloyed with gold that actually reacts with or to oxygen, sulfur and moisture and at times discolors or tarnishes and makes your gold jewelry black.
Gold tarnishing is the slight corrosion of the gold surface and is evident as a dark discoloration of the gold item, also called a tarnish film. Real gold jewelry can sometimes tarnish or become black and discolor. But usually the higher the percentage of gold in the alloy, it is less likely for the gold jewelry to discolor or become black.
5 common reasons that will trigger gold to tarnish or become black:
When base metals alloyed with gold reacts with or to oxygen it can discolor or tarnish your gold jewelry. Oxidation is a chemical reaction in which electrons are lost. Also, oxidation takes place depending on the type and manufacturing process involved in making the gold jewelry. For example, in Pachi work, silver foil is used for making the gold jewelry. After some time, the silver in the pachi gold jewelry can react with or to oxygen and cause the jewelry to become black. The same goes for Kundan jewelry. Kundan is basically a certain type of workmanship in which gold foils are used between the gem stones in making the jewelry. To get this type of workmanship done, the alloys that are used to mix with gold are highly reactive with oxygen and can turn black over a period of time. There are also some cases of blackening of 21 and 22 karat gold jewelry. Usually gold items that are made with alloys such as copper or silver may tarnish the 22K gold jewelry and turn them black.
22K gold jewelry can discolor when it is in contact with human sweat. Perspiration, which is essentially rich in sodium chloride – common salt, can cause tarnishing of the gold jewelry. Human sweat is 99% moisture, and 1% is human waste and hazardous substances in the body, such as: chlorinated, lactic acid, urea, ammonia, etc. These substances after contact with gold jewelry having silver and copper alloys can produce chemical reaction to produce silver chloride and copper sulfide, which can lead to creation of deep black chemical salts. This chemical reaction can discolor the 22K gold jewelry and make it black.
3. Body Care Products, Perfumes & Pain Relief Ointments:
Synthetic ingredients and chemicals found in most bottled fragrances like perfumes, body creams, body oils, lotions, moisturizers, deoderants, pain relief ointments - like Blue Emu, Bengay, balms, hot packs, ice packs, and gel packs can all discolor 22K gold jewelry, pearls, diamonds, and other gem studded pieces.
4. Food Products:
When 22K gold jewelry is in contact with some food items containing acid and/or sulphur compounds like fruit juices, oil, viniger, soda, pickles and onions it can discolor or tarnish the gold jewelry and make it black.
5. Cleaning Substances:
People aren't aware of the damage bleach and chlorine can cause to 22K gold jewelry. Both cause a chemical reaction that disintegrates the alloys in the jewelry over time. Gold jewelry can also darken when it is frequently exposed to bath gel, shampoo, soap, lotion, rubbing alcohol, hyderogen peroxide and everyday grime.
Tips/ Preventive Measures:
- Keep 22K gold jewelry in closed boxes and containers. For patchi and kundan jewelry, do not keep them in the jewelry boxes, rather keep them wrapped in a soft cloth.
- Also, when your 22K gold jewelry discolors, becomes black or tarnishes we recommend you take your jewelry to a jeweler who can repolish your jewelry and make it look new again!!