Precious metals - metals are not subject to corrosion and oxidation, which distinguishes them from most metals. They are also precious metals, due to their rarity. The basic precious metals - gold, silver, and platinum and the other 5 platinum group metals - (ruthenium, rhodium, palladium, osmium, iridium). Some authors refer to the noble metals as well technetium, which does not occur in nature (besides, he's radioactive with a small half-life).

Interesting facts about gold, platinum and silver

Gold is so rare metal that one hour in the world are more iron than in the entire history found gold.

Platinum previously considered "wrong silver" and were thrown into rivers or the sea, not to get under your feet. Only later, when jewelers from Spain found that platinum well-alloyed with gold, it was used as jewelry materials.

"Aqua Regia" - so is called a mixture of hydrochloric and nitric acids. This "cocktail" dissolves the gold.

Interestingly, native silver occurs much less frequently than native gold, but the total number of gold on Earth, much less than silver. Such is the paradox.

In 1828 the year in Russia issued platinum coins 3.6 and 12 rubles. At that time platinum cost half the price of silver.

Gold is an excellent conductor, therefore, is the most important raw material in electrotechnical industry.

In Russian - "silver", in English - "silver", German - "Zilber" - all these words come from the Indian word "Sarpa," which meant the moon and sickle.

In Ancient Egypt, the gold was considered the particles of the gods, so to speak were not permitted to anyone except the Pharaoh.

The largest sterling silver nugget was found in Chile and weighed 1420 kg

Precious metals such as gold, platinum, silver and palladium do not enter into chemical reactions with the body. That is why these metals is actively used in medicine and jewelry industry.

Olympic medals, awarded in 1912, were made of pure gold. In the modern world of sports medals cover only 6 grams of this metal.

In 1933, Frank Roosevelt signed the decree which prohibited US citizens to hold gold. Violation of this order is punished by a fine of 10 thousand dollars or ten years of imprisonment.

Gold 999 so soft that it can easily be scratched with a fingernail.