Discovered in the tombs of the 12th dynasty Egyptian pharaohs (2000 BC), platinum was also known to the Central American Indians. Between 1828 and 1844, platinum coins were minted in Russia.
Although initially not given much attention, platinum is today one of the most valuable gemstones. Rare and mysterious, platinum is a dense and stable metal, often used in the jewelry industry due to its attractive appearance, as well as in the medical, electronic and chemical industry due to its varied and unique chemical and physical properties.
What is Platinum?
Platinum is a silver-white transition metal found in deposits in riverbeds. In appearance it resembles silver, but on the periodic table it appears closer in structure to other rare and heavy metals, such as rhodium, palladium, iridium, rutenium and osmium.
It is a shiny and very stable metal, remaining unaltered under the action of air, water and most acids. It is malleable and is used in many fields, from jewelry to electronics, from dental appliances to the armaments industry. Platinum absorbs hydrogen, as does palladium. Platinum and cobalt alloys are magnetic.
Regarding the density of metals, platinum reaches 21.45 g / cm3, being considered a heavy metal. Platinum is part of the category of noble metals, and not just precious, as is the case with silver. Noble metals have a very good resistance to corrosion and mention their shine over time. Probably for this reason, most couples who decide to get married choose platinum or gold rings instead of silver ones.
Platinum jewelry retains the pure white hue of the metal forever, even when not worn in ideal conditions. A gram of platinum is more expensive than a gram of gold, but cheaper than a palladiumor rhodium.
What are the characteristics of platinum?
- Atomic symbol: Pt
- Atomic number: 78
- Chemical category: transition metal
- Melting point: 1768.3 ° C
- Hardness on the Moh scale: 4-4.5
Where is platinum found?
The largest platinum producers in the world are: USA, Canada, South Africa and Canada.
How is platinum extracted?
Typically, miners extract platinum from platinum-containing ores by crushing them in a solution of water, allowing the platinum particles to detach from the ore and float in the water. Then the air is pumped into this water. Platinum particles attach to oxygen and rise to the surface, from where they are collected and left to dry.
Once dry, the powder is heated to a temperature of 1500C ° in electric furnaces where the particles of iron and sulfur, nickel, copper and cobalt are removed by electrolytic and chemical processes.
In the next stage the concentrated ore is dissolved in royal water (a mixture of nitric acid and hydrochloric acid), from which chloruplatinic acid is obtained which will then be burned to obtain pure platinum. The same procedure is used for obtainingpure gold.
What is the history of Platinum?
A theory published a few years ago says that gold and platinum “fell” to Earth as a result of a meteor shower more than four billion years ago, and precious metal deposits appeared during the formation of the Earth, when the molten iron was attracted to the center, carrying with it vast quantities of precious metals.
How was platinum discovered?
An Egyptian sarcophagus dating from around 700 BC. it is decorated with jewelry made of metals from the platinum group. This is the earliest use of platinum, although Aboriginal people in South America used gold ornaments and platinum alloys before they were discovered by Columbus.
Spanish conquistadors first encountered platinum in the 16th century, disappointed at first that it was not silver, which at the time was well known as a precious metal. Initially the conquerors thought it was a metal inferior to silver and named it “platinum”, meaning “smaller silver”, but as the newly discovered metal was stronger than iron, more beautiful and unusually heat-resistant, they brought it. with them at home in Europe.
In 1557, the Italian humanist Iulius Scaliger wrote about this strange metal that no furnace can melt, but only in 1783, the first to obtain a sample of pure platinum was Francois Chabaneau.
In 1803, the Englishman William Wollaston discovered the modern method of extracting metal from ore, a method that has remained almost the same to this day. William Hyde Wollaston discovered two other metals: palladium and rhodium. Platinum quickly found its place in the market for precious metals and jewelry, and the growing demand for platinum led to what has historically been called the “Platinum Age of Spain”.
The largest platinum deposit in the world
The growing demand led to the discovery of significant deposits in the Ural Mountains in 1824 and in Canada in 1888, but the greatest discovery came in 1924, when a platinum nugget was discovered in the bed of a river in South Africa. to the discovery of the Bushveld volcanic complex, the largest platinum deposit on Earth, which today supplies about 75% of the platinum quantity on the market, with Russia and Zimbabwe supplying the rest.
What are the uses of platinum?
Platinum is a metal with many useful properties, which explains its use in a wide range of industries.
It is one of the densest metals – almost twice as dense as lead – and very stable, which gives it excellent anticorrosive properties.
It is a good conductor of electricity, it is malleable and ductile (it can be processed into very thin sheets or wires). For a metal produced in such a small amount (around 190 tons per year), platinum is used in many common utility products.
About 40% of the demand is represented by the jewelry industry where it is mainly used for the production of white gold. In addition, platinum is used in itself to make jewelry.
In the automotive industry
Platinum’s resistance to corrosion and stability at high temperatures make it the ideal catalyst for chemical reactions. Due to this aspect, platinum is used in the automotive industry. Catalytic converters reduce harmful emissions, triggering reactions that convert over 90% of hydrocarbons into less harmful compounds.
In medicine and laboratory equipment
Platinum is considered a biologically compatible metal because it is non-toxic and stable and does not react negatively in contact with human tissue. Recent research has shown that platinum appears to inhibit the development of certain cancer cells.
In the medical industry the demand is increasing for platinum, due to the conductive properties for the manufacture of electrodes for pacemakers, as well as for retinal implants, but also in the pharmaceutical industry.
In the electronics industry, for electrical contacts
In the electronics industry, platinum is used to make semiconductor crystals for lasers, while various alloys are used to make magnetic disks for hard drives and contacts for lasers. car remote controls.
White Gold vs. Platinum
Usually, platinum is marked on jewelry with “PT” or “PLAT”. Sometimes the purity of platinum is also marked, either “PT 900” – when the purity is 90% platinum and 10% other metals, or “PT 950”, or “PT 999”.
Platinum, white gold and silver – three different precious metals:
– Platinum (Pt) is the rarest and most precious of the 3.Platinum is currently about 50% more expensive than gold. Platinum is naturally white and scratch resistant.
– White gold (Au) is an alloy of gold with other metals, but gold has the largest proportion.
– Silver (Ag) is the cheapest, about 2.5% of the price of gold and 1.67% of the price of platinum.
– Platinum is about 40% denser than white gold, much more durable and heavier. – Platinum is 30 times rarer than gold.
– When scratched, platinum does not lose weight, because the metal is not lost, but redistributed. – Platinum is the most ductile of pure metals. Only gold is more malleable. – Platinum is about 60% heavier than 14K gold. Thus, if we have two identical jewels, the 14K gold one will weigh 10g and the platinum one will weigh 16 g. – The platinum has a purity of 95%, and the gold has 91.6% (18K), 75% (the 18K one) or 58% (14K) – The word ‘platinum’ is often associated with increased wealth and value.