Gold - one of the rarest metals on the planet, has long been considered a symbol of wealth, success and high standing in society. In the periodic table D.I. Mendeleev, he is referred to as Aurum, that is, "golden", and in the people it is also called "noble." And this is no coincidence, because gold is an inert metal, practically does not enter into chemical bonds and does not form new compounds - it behaves like noble layers of society.
It was the inertness of the metal that caused its high cost and relevance. However, despite the "hostility" to other elements, scientists managed to create various types of gold, which are now used in many industries, from jewelry to instrument making. In its pure state, it is now almost impossible to meet.
Gold content
In nature, gold is not found in the form of “shining” coarse clastic rocks, but in the form of minute inclusions, grains of sand, located inside the main, gold-bearing rock. Sometimes grains of sand are so small that they can only be seen with the help of special equipment.
But there are also nuggets, the largest of which - the "Desired Stranger" - was found in Australia and weighed about 75 kg. And when gold mining was conducted in the Urals, a sample weighing 35 kg was found, nicknamed the "Big Triangle".
But gold enters the market only after multi-level refining. But even after enrichment, the raw material contains a certain amount of impurities. Because of this, the first types of gold appeared, which differed among themselves by breakdown - by the percentage of metal in the product.
Gold Sample Systems
Government agencies use the purest samples of this metal as gold reserves. The percentage of the element in them is 99.999% per gram of substance. But a standard 1 kg bank ingot contains 999 grams of metal. It is the value of this ingot, divided by a thousand, that can be observed on the gold and currency exchanges of the planet.
A sample of gold is indicated on the product itself in the form of a small stamp indicating quite specific numbers. Two sample systems are used in the world:
- Metric Distributed in the CIS, European countries and in Russia, numerical designations are used.
- Carat used in the countries of the European Union and the USA. It determines the number of parts of gold that falls on 24 parts of the alloy.
In the carat system, pure gold (percentage of more than 99.9%) corresponds to 24 samples, and in the metric - 999th.
If on a gold product you notice a mark with the numbers "750" or 18 carats, then the product contains 75% of the noble metal. Jewelry
585 samples are most common in the post-Soviet space. And the lowest quality is considered to be 9 carat or 375 samples of the product, because in their composition no more than 37.5% of gold.
"Spectrogram" of gold products
In its pure form, gold is a very soft, plastic and malleable material that literally "melts before our eyes" and is difficult to process. In order to give shape to the gold raw materials, various metals are added to it : silver, copper, cadmium, chromium, platinum and others. Thus, various types of gold, or rather its alloys, are obtained.
Depending on which element was added to the raw materials, the physical properties of the alloy, as well as its color, are found. The hue of gold products can be the most diverse, can vary from gold, yellow and pale pink, to dark blue, brown and even black. All this ultimately determines the cost of jewelry and their aesthetic qualities.
Yellow and white gold
Yellow gold is the most traditional and common alloy in the world. In it, silver and copper are added to a noble metal in a different ratio. It is the amount of impurities that determines how much gold costs in the jewelry market. If the percentage of silver exceeds the amount of copper, then get products even lemon color. If there is more copper, then a red tint appears. The most common products on the market are 585 and 750 samples.
White gold is considered the most expensive and beautiful alloy, which is not surprising. To obtain it, palladium or platinum is added, which is why the products become whitish. In addition to color, the strength characteristics also change - they become higher. For
jewelry , white gold 585 and 750 are used.
Red and pink gold
Red gold is obtained by adding a large amount of copper to the alloy. In some products, the content of additives can reach 50% of the total mass. That is why all types of red gold are of low cost. It looks good with red gems - rubies and garnets.
To obtain a pink tint, from 3 to 2 parts of silver are added to the alloys, together with copper. Color emphasizes nobility. That is why this material is popular among many jewelry houses in the world that make jewelry for celebrities.
Green and Blue Gold
There are several ways to get green gold. The most common of these is the balanced addition of silver to the alloy. As this metal is introduced, the shade changes - the products acquire a green, yellow-green and pure white color. How much the green gold is worth depends on this. If the percentage of silver reaches 30%, a new mineral is formed - electrum.
To obtain blue gold, steel or cobalt is added to the alloys. In the first case, the hue changes from light gray to cold blue. When cobalt is added, the alloy begins to acquire a bluish tint. Some jewelry houses achieve a similar effect with rhodium plating.
Here, far from all alloys are presented that characterize what types of gold are. Black noble material, as well as its brown and brown shades, are very popular in the world.