The Egyptians called gold "sunshine." Since ancient times, this precious metal had a mystical surroundings. He was worshiped, gold served as a measure and a symbol of wealth. Today, the jewelry market has been flooded with gold-like items. However, this is not gold products, but the so-called medical gold.
What kind of alloy is this, what is its relation to medicine - let's try to figure it out. And is medical gold really valuable, the price of which seems more than acceptable to the average layman. 
Pure gold
In nature, there is no such metal as pure one hundred percent gold. Mankind extracts it from native forms or gold ores, in which the content of 10-50 grams of gold per ton of gold ore is considered very promising.
The most gold-containing compound can be considered only crystals grown artificially in a chlorine atmosphere by a complex method of chemical transportation. And even in these crystals the gold content is 99.9%.
The chemical substance Aurum (Au) is a yellow metal. Very soft and ductile, with high density. The inertness of gold, that is, the absence of interaction under normal conditions with acids, makes it a noble metal. All precious metals are subject to mandatory testing with the appropriate affixing of the mark. It is a test of gold, and this is the stigma, which means the proportional content of the precious metal in a particular product.
Natural gold consists of the stable Au isotope (197). There are other isotopes - radioactive. For example, Au (198) has found application in radiology in the treatment of cancer. 
Medical gold - no test
As is clear from the previous text, all the gold on the planet is presented in the form of alloys with different gold contents in them. The term "medical gold" means a certain marketing line, including products with different coatings and medical steel. What is the difference between medical gold and ordinary?
The lowest allowable breakdown for jewelry is considered to be 375 gold samples. And for everything that contains less gold than this sample, the term “medical gold” has been introduced.
The value of medical steel
In medicine, for the production of high-strength and durable tools, a special alloy is used without a fixed composition of the following components: iron, copper, nickel, magnesium, manganese, sulfur, chromium, brass, zinc, silver and molybdenum. Such an alloy is called medical, or surgical, steel. Tools from such alloys are not scratched and have high strength and anti-corrosion properties.
Medical, or surgical, steel is divided into four groups:
- Prevalence in the alloy of nickel, chromium and magnesium (sample 200).
- The alloy contains only chromium and nickel (sample 300).
- High concentration nickel alloys.
- In an alloy only chrome.
For dentistry, an alloy of nickel-chromium or cobalt-chromium is used, and an alloy based on silver is used for piercing. Composition and proportions may vary depending on the desires of the consumer. 
How steel becomes medical gold
As a result of two types of coatings, medical steel becomes similar to gold products. The method of turning steel into medical gold differs in its physical characteristics and can be of two types:
- Gold Plated method - plating by spraying. Inexpensive and fragile spraying, which is easily susceptible to mechanical damage.
- Gold Filled method - applying gilding under the influence of high temperature (up to 900 degrees). Expensive and durable coating.
This is how a medical alloy for gold is formed, which is used in the manufacture of jewelry. Manufacturers usually indicate the polishing method on products or instructions for them.
Medical Gold Jewelry
Jewelers create real masterpieces from this inexpensive, yet durable and sought-after material. The combination of matte and mirror surfaces, inlay and engraving, giving the color of platinum - all these techniques allow you to make rings, earrings, bracelets, necklaces unique. In addition, figures come to life and roses bloom with gold. And by the way, the low price for such products.
Customer reviews are positive. In addition to the consumer price, such products have a number of other advantages over gold and silver jewelry. 
Advantages and benefits
As already mentioned, the invention of medical gold has given a number of advantages to all jewelry lovers.
Visually, products from such a material are difficult for a layman to distinguish from 750 gold samples. Most importantly: they do not blacken and remain in their original form for a long time. Even if the owner swims in the pool with chlorinated water and is actively involved in sports.
It is also important that this is a way out for people who are allergic to all metals except gold. Almost everyone can afford such jewelry. 
Application area
Jewelry and medicine are not the only areas of human activity, where medical gold, by the way, is characterized by the variability of the main alloy.
Without medical gold and surgical steel, the beauty industry would have lost many of its achievements: gold threads in face and body correction, wraps and masks with gold particles, cocktails with gold plates and much more.
Gold plating in brands of famous brands
If the reader has an opinion, medical gold is not in consumer demand among the richest part of buyers - here are a few facts to think about.
Well-known jewelry brand BVLGARI has released a collection of 18-carat Diamonds rings in gold and inlaid with zirconium stones.
Cartier brand in the Trinity ring collection confidently holds a leading position with a designer find in the form of three intertwined rings with pink, yellow and white plating with high carat gold.
The latest Laligue Gold Luster Collection is presented with exquisite interior animal figures and other luxurious objects with a noble golden surface. 
The beauty of hands and feet, caring for them is unthinkable without tools for manicure and pedicure. Any professional hairdresser accessories store will present a wide selection of alloyed and gold-plated instruments. They are able to tolerate repeated sterilization, which makes them durable and in demand.
After reading the article, everyone should understand what medical gold is and its composition, and why there is no test on jewelry. However, this does not mean the lack of noble medical gold. Given the contribution of this simple alloy to medicine and social alignment, it is entirely possible to rank medical gold as a grand invention of mankind.